Assembly of reservoirs for washing water for vehicle windows.

The assembly has main and auxiliary water reservoirs (2, 3), where the reservoir (3) has a connection neck (9) engaged in a communication orifice (10) of the main reservoir when the reservoirs are placed side by side. The outer wall of the main reservoir has a projecting rib (7) suitable to cooperate with a hollow groove (8) of same profile arranged in a wall of the auxiliary reservoir to mutually integrate the reservoirs.