At the end of the turn in which another Pokémon used a one-time use item (including throwing an item with Fling or using Natural Gift), a Pokémon with Pickup will collect the item if they are not holding anything. If more than one Pokémon has Pickup or Harvest, the faster Pokémon will restore an item first. If multiple items can be collected, the Pokémon will collect the item most recently consumed.
A single Pokémon's Pickup will not activate more than once per turn.
Pickup cannot collect an item if the Pokémon that consumed the item is no longer on the field at the end of the turn, or if the item has already been recovered (such as with Recycle, another Pokémon's Pickup, or Harvest). Pickup cannot collect an item that a Pokémon consumed before switching out, even if it switched back in again before the end of the turn. Pickup cannot collect items that have been destroyed with Incinerate, eaten with Bug Bite or Pluck, or knocked off with Knock Off. A popped Air Balloon cannot be collected.
A Pokémon may only have one consumed item at a time; if a Pokémon consumes an item, obtains another item and consumes it, the original consumed item cannot be collected, even if the second item is collected or restored then swapped away. If the Pokémon obtains another item after consuming an item, Pickup can still collect the old item as long as the Pokémon does not consume the new one.
Outside of battle
After winning a battle, any Pokémon on in the player's party that has this Ability and is not already holding an item has a 10% chance of creating a held item for itself, even if it did not participate in the battle. The Pokémon can find an item even if it is fainted.
This section is incomplete. Please feel free to edit this section to add missing information and complete it. Reason: needs more information on which items can be found in each dungeons.
Each time the player enters a floor, a Pokémon with Pickup will have a small chance of finding an item that can appear on that floor (other than Poké) as long as it is not holding an item. In Explorers of Time, Darkness, and Sky, Pickup will not activate prior to obtaining the Treasure Bag.
In Rescue Team DX, it can find items even when it is holding something, as the effect has been revised to put items found using the Ability into the Toolbox. If the Toolbox is full, the item found is placed on the floor instead. Pickup works for Makuhita Dojo, even though items do not spawn on the ground.
The Pokémon may pick up an item when it goes to a different floor.* When the Pokémon goes to a different floor, it may pick up an item! But if it is already holding an item, it won't pick up anything.*