Throughout Final Fantasy II, you'll need to rely on Items here and there to aid you in your quest. Unfortunately, being one of the earlier games, there's not a whole lot of Items for you to use and even the ones that are important cost a fortune just for 1 of them. (5,000 Gil for ONE Phoenix Down?!) Anyway, here's a list of all the Items in the game and exactly what each does.
Item Name: Acid Bottle. Information: Casts Venom. Where it's found: Various.
Item Name: Antidote. Information: A potion that cures Poison/Venom. Where it's found: Various.
Item Name: Bacchus's Wine. Information: Increases one person's Strength. Where it's found: Various.
Item Name: Backstabber. Information: Casts Muddle on an Enemy. Where it's found: Various.
Item Name: Black Mask. Information: A black mask that's used on the Firion Doppelg�nger in the Mysidian Cave. Where it's found: Tropical Island.
Item Name: Canoe. Information: A canoe used to cross rivers and lakes. Where it's found: In Altea once Mindu joins your party.
Item Name: Cottage. Information: A cottage that when used on the World Map, fully recovers your party's HP and MP. Where it's found: Various.
Item Name: Cross. Information: A potion that cures Curse. Where it's found: Various.
Item Name: Crystal Rod. Information: A crystal rod used to unseal the Mysidian Tower. Where it's found: Mysidian Cave.
Item Name: Dragon Egg. Information: An egg that's the last of the Wind Drakes. Where it's found: Deist Castle.
Item Name: EGil's Torch. Information: Used to carry the Sunfire. Where it's found: Kai'son Castle.
Item Name: Elixer. Information: A potion that fully recovers one person's HP and MP. Where it's found: Various.
Item Name: Ether. Information: A potion that restores a VERY small amount of MP. Where it's found: Various.
Item Name: Eye Drops. Information: A potion that cures Darkness. Where it's found: Various.
Item Name: Gaia Drum. Information: Casts Earthquake. Where it's found: Various.
Item Name: Garlic. Information: Damages Undead Enemies. Where it's found: Various.
Item Name: Goddess's Bell. Information: A bell used to open the gate in Kai'son Castle. Where it's found: In the Snow Cavern after beating Adamantoise.
Item Name: Gold Needle. Information: A Item that curse Stone. Where it's found: Various.
Item Name: Hellfire. Information: Casts Fire. Where it's found: Various.
Item Name: Hermes. Information: Casts Haste on one person. Where it's found: Various.
Item Name: Hourglass. Information: Casts Stop. Where it's found: Various.
Item Name: Hi-Potion. Information: A potion that recovers a large amount of HP to one person. Where it's found: Various.
Item Name: Magiconch. Information: Casts Shell on one person. Where it's found: Various.
Item Name: Maiden's Kiss. Information: A Item that cures Toad. Where it's found: Various.
Item Name: Mallet. Information: A hammer that cures Amnesia. Where it's found: Various.
Item Name: Mute Bell. Information: Casts Silence. Where it's found: Various.
Item Name: Mythril. Information: A special type of metal used to create weapons/Armour. Where it's found: In Semitt Falls after defeating Sergeant.
Item Name: Mythril Mirror. Information: Casts Wall on one person. Where it's found: Various.
Item Name: Notus. Information: Casts Ice. Where it's found: Various.
Item Name: Pass. Information: A pass that lets you board the Dreadnought. Where it's found: In Bafsk Cave after meeting Dark Knight and Borghen.
Item Name: Pendant. Information: A Pendant used to talk to the Wind Drake and to also summon the final Wind Drake. Where it's found: In Deist Cavern.
Item Name: Phoenix Down. Information: A Item that cures K.O./revives a character. Where it's found: Various.
Item Name: Potion. Information: A potion that cures a very small amount of HP. Where it's found: Various.
Item Name: Ring. Information: A ring that lets you view the World Map and also show to Hilda that Scott is dead. Where it's found: In Fynn.
Item Name: Sage's Wisdom. Information: Increases one person's Intelligence. Where it's found: Various.
Item Name: Saint's Spirit. Information: Increases one person's Spirit. Where it's found: Various.
Item Name: Silk Web. Information: Casts Slow. Where it's found: Various.
Item Name: Slumber Stalk. Information: Casts Sleep. Where it's found: Various.
Item Name: Snow Craft. Information: A vehicle that lets you travel across the snow. Where it's found: Semitt Falls, after Josef joins you.
Item Name: Sunfire. Information: A fire so strong, it's the only thing that can bring down the Dreadnought. Where it's found: Kai'son Castle.
Item Name: Thantos. Information: Casts Fear. Where it's found: Various.
Item Name: Unicorn Horn. Information: Casts Basuna on one person. Where it's found: Various.
Item Name: White Mask. Information: A white mask that's used on the statue in Mysidia. Where it's found: In Fynn Castle.
Item Name: Wind Drake. Information: The last Wind Drake that's used to bring you into the Cyclone. Where it's found: Fynn Castle.
Item Name: Zephyr's Flute. Information: Casts Cyclone. Where it's found: Various.