Watchmaker's portable lubrication tool including at least one lubricant reservoir, with a plurality of chambers, each only accessible to a user in a first open position of the tool, each reservoir being closable by a sealed lid which, in a second closed position, is kept sealingly pressed on the reservoir, and the tool includes a structure which carries such a lid associated with such a reservoir, and which is a component of a multi-function pocket knife of the “Swiss army knife” type, with a frame on which pivots a plurality of blades, the tool comprises at least one elastic return arranged to exert, in the second closed position, a force on at least one lid to press it sealingly on an associated reservoir.