Select controller:All items are equipped by holding 
to access the items menu, and selecting the desired item with 
. You can quickly equip and un-equip the most recently-used item with 
.
Magnifying scope
One of the items you begin the game with. The magnifying scope, as the name implies, allows you to zoom in on distant objects while in first-person view, helping you to plan your route through the game. Zoom in with 
, zoom out with 
, and look around with . You cannot move while using the scope.
ID Card
One of the most important items in the game. The ID card is used as a key to the doors of the facility. You cannot access a door that is of a higher security level than the card you currently own (i.e. a level 4 ID card can open all doors between levels 1-4, but not doors of levels 5-7). The card must be equipped with in order for locked doors to detect it. There are seven levels of ID cards in the game.
- Received from DARPA chief Donald Anderson after finding him in the cells in the tank hangar.
- Received from ArmsTech president Kenneth Baker after defeating Revolver Ocelot.
- Found on a dead enemy soldier's body after defeating the M1 Abrams tank.
- Received from Otacon after defeating the Cyborg Ninja.
- Received from Meryl after you find her on floor B1 of the nuclear warhead storage building.
- Received from Otacon while imprisoned after Ocelot's torture session.
- Received from Vulcan Raven after defeating him.
PAL Card Key
Another major item, received from Meryl after you find her on floor B1 of the nuclear warhead storage building. This item's purpose is to deactivate Metal Gear REX's launch codes. There is a special trick to using the key: it must first be used at room temperature, then frozen, then heated up.
Optical disc
Received from ArmsTech president Kenneth Baker after defeating Revolver Ocelot. This optical disc contains the data from Metal Gear REX's test launch. It is completely useless in terms of gameplay; its only purpose is to advance the storyline.
Ration
Found in several locations on Shadow Moses Island, and sometimes as a random drop by defeated enemies. When eaten, it restores a little of your health. To use, hold to open the items menu, highlight it, and press to eat. The maximum number of Rations you can carry at one time is proportional to your maximum health; therefore, the maximum Ration capacity increases when your maximum health increases after defeating a boss. Rations may become frozen in extremely cold areas; to melt them, equip them with as you would any other item, and wait for them to defrost. If your Life runs out while having a Ration equipped to , one ration will automatically be used to replenish your health.
Cardboard Box
One of the most famous items in the Metal Gear series. The Cardboard Boxes can be used to hide from enemies when no other hiding place is available. It's possible to move around while wearing a cardboard box, though, obviously, a box that suddenly grows legs and runs off is bound to raise suspicion, so only move when the enemy isn't looking in your direction. While hiding in a box, you can't use weapons, but you can use first-person view (hold 
) to look for enemies.
Equipping a box while in the back of a cargo truck will get you delivered to the location marked on the label of that box. This allows the player to skip the laser grid and the mine filled canyon for backtracking to the Armory for Psg-1 by using boxes A and B.
If the player punches Meryl after she teases Snake at the end of the cave area and immediately equips a box the wolf pup will urinate on it granting the same effect as the handkerchief making all wolves passive while it is equipped. There are three types of cardboard box in the game, the only differences between them being the colour of the stripe at the bottom of the box, and its label.
- Cardboard Box A: Found in a level 1 room just up the stairs near the elevator on floor 1 of the tank hangar. Addressed "To Heliport". Has a reddish-brown stripe on it.
- Cardboard Box B: Found in the top left level 4 room on floor B1 of the nuclear warhead storage building in the area where Meryl is patrolling in disguise. Addressed "To Nuclear Warhead Storage Building". Has a yellow stripe on it.
- Cardboard Box C: Found in the southwestern most level 6 building in the Snowfield near the cargo truck after defeating Sniper Wolf for the second time. Addressed "To Snow Field". Has a blue stripe on it.
Suppressor
The SOCOM Suppressor is found in Tank Hangar 1F in a level 2 room with a sleeping guard in the northeast corner near the cargo door. If SOCOM is equipped when found, it is automatically attached to the SOCOM upon picking it up. If not, equip the suppressor from items menu then equip the SOCOM in the weapons menu to attach it. It allows you to take out enemies silently from a distance making it one of the best tools in the game.
Thermal goggles
The thermal goggles are found on the east side of the upper area of floor 1 of the tank hangar near the upper air duct entrance in an open room with a surveillance camera, but only if you found the SOCOM in the cargo truck at the heliport or they will be moved to the level 6 room in Nuclear Warhead Storage Building B2 where body armor would be. The thermal goggles reveal hidden laser wires, pitfalls, claymores, and enemy soldiers disguised with stealth camouflage.
Night-vision goggles
Found on floor B2 of the nuclear warhead storage building, inside a level 4 room. As the name implies, the night-vision goggles greatly increase visibility in darker areas such as the cave that leads to the first Sniper Wolf battle.
Mine detector
Found in a level 2 room on the upper area of floor 1 of the tank hangar near the room with the thermal goggles, a level 7 room in the Underground Warehouse North, or in Underground Base 3F. The mine detector makes the locations of hidden Claymore mines appear on the Soliton radar. Since it relies on the radar being functional, it is useless in areas where the radar cannot operate. The thermal goggles can be used to find claymores as well, so this item is mostly redundant. However, when the PAL key is dropped on normal mode and higher it is eaten by a rat and you will need this to track its movements.
Gas mask
Found on floor B2 of the nuclear warhead storage building after disabling electrified floor in the last level 3 room on the right that is guarded by a camera. The gas mask reduces the speed at which your oxygen is depleted in rooms containing toxic gas. It is very good to have this after entering all three PAL codes on disc 2.
Diazepam
Found in Nuclear Warhead Storage Building B1, Cave, Snow Field, and Northeastern most building in Snow Field. Diazepam is a drug used to steady your aim while using the PSG-1 sniper rifle. It has no noticeable effect when not aiming the PSG-1. To use, hold to open the items menu, highlight it, and press to take.
Cold medicine
Found on floor B1 of the nuclear warhead storage building. Only used to cure Snake if he catches a cold while imprisoned and stripped of the top of his Sneaking Suit (if he has, he'll sneeze every few seconds, making it harder to stay hidden). To use, hold to open the items menu, highlight it, and press to take.
Body armour
Found by making a detour to floor B2 of the nuclear warhead storage building after being captured instead of heading directly to underground passage. It's located in a level 6 room guarded by gun cameras along the path nikita missiles took to destroy electrical switchboard earlier in the game, but only if you picked up thermal goggles from tank hangar. If it was missed then it's moved to the beginning of disc 2. Reach the door that leads to the cargo elevator in the blast furnace but head south instead to a room with pipes shooting out steam. Crawl through the vent at the bottom left side of the screen to collect it from this area. The body armour is a bulletproof vest that reduces all damage taken while equipped.
Rope
Mandatory for progressing past the Comm Towers. A one-time-use item located on the ground floor of Comm Twr A, immediately after triggering the scripted Alert. It is only used for the rappelling sequence on the roof of Communications Tower A.
Cigarettes
One of the items you begin the game with. Cigarettes, while equipped, slowly deplete your health. Cigarette smoke, however, can be used to reveal hidden laser wires. They are only useful if you failed to find the thermal goggles, because of the hazard to your health.
Timer bomb
Found in your inventory after escaping the cell after Ocelot's torture. This item is only bad news: if the timer runs out, it'll explode and kill you instantly. Dispose of it as soon as possible by opening the items menu, highlighting the bomb, and pressing .
Camera
Found in the south area of the armoury (floor B2 of the tank hangar), east of where you fought Revolver Ocelot. Completely optional as far as beating the game is concerned. The camera functions similar to the magnifying scope, but with the added ability to take photographs with 
. It is the only item found through normal gameplay that is automatically available from the beginning of the second and subsequent playthroughs on the same save file. Photographs can be viewed by selecting "Album" from "Special" on the game's main menu.
Stealth camouflage
Received from Otacon during the game's ending, if you submitted to Ocelot's torture sessions; therefore, it is one of only two items completely unavailable during your first playthrough, but is permanently available during all subsequent playthroughs on the same save file. The stealth camouflage renders you completely invisible, except for your shadow and your weapon, thereby greatly reducing the difficulty of repeat playthroughs. Enemies will still notice sounds you make, but the apparent lack of source immediately puts them off your trail. The stealth camo also renders weapons such as chaff grenades obsolete, as you can simply use the stealth camo to avoid detection by security cameras. However, the stealth camo generally does not work against bosses.
Infinite-ammo bandana
Received from Meryl during the game's ending, if you did not submit to Ocelot's torture sessions; therefore, it is one of only two items completely unavailable during your first playthrough, but is permanently available during all subsequent playthroughs on the same save file. The infinite-ammo bandana, while equipped, does exactly what it says on the tin: your weapon ammunition will never be depleted, and you'll never need to reload, either.
The Twin Snakes exclusive items
Bandage
Found in several areas. Use when your life meter turns orange to stop bleeding. If you don't do so, enemies will notice the trail of blood behind you, and find you easily.
Dog tag
Received by holding up certain guards, or checking the bodies of certain bosses. Completely unnecessary for completing the game. A list of collected dog tags can be viewed by selecting "Dog Tags" from "Special" on the game's main menu.
AP Sensor
Found underwater in the Cargo Dock. While equipped, this will cause the controller to vibrate when enemies are nearby. Only useful if you have chosen to play without the radar, or the radar is unavailable. Useless if you're using the Wavebird, due to the Wavebird's lack of a rumble feature.