Plant for washing trolleyed objects provided with a head wall. The plant comprises a washing chamber to wash the trolleyed objects, and an extraction device working under traction, to extract the trolleyed objects from inside the washing chamber to an unloading zone outside the washing chamber. The extraction device comprises an unloading structure defining the unloading zone, a movement mechanism assembled on an upper wall of the unloading structure, and an extraction arm assembled on the movement mechanism and provided with attachment members which cooperate from above with the head wall. The movement mechanism moves the extraction arm between a first position, in which the attachment members are inside the washing chamber and cooperate from above with the head wall, and a second position, in which the attachment members are outside the washing chamber and carry out the extraction of the trolleyed object.
