The cap reservoir and dropper assembly for bottles includes a reservoir (1) fitted with a collar 913) adapted for resting on the mouth of a bottle (4), a delivery piston (2) the lower part of which is shaped like a flute mouthpiece (24) and the upper part of which is shaped like a collar (22). The assembly further includes a cap (3) the lower part of which is in the form of a removable strip (33). The delivery piston is equipped in its upper part with a dropper (23). The cap may be equipped with a feature which cooperates with the delivery piston collar to push the delivery piston downwards.