A quick acting coupler for a cultivator attachment, such as a cultivator fender, shield, or the like, in which the attachment is carried by a mounting frame with the latter being securable to the tool or cultivator bar of a cultivator implement for coupling of the attachment to the cultivator at a desired location on the cultivator. The coupler includes a hitch member for each attachment, each hitch member being securable to the tool bar of the cultivator at a desired position therealong. The mounting frame is connected to the hitch member by inserting one or more headed pins carried by the mounting frame into corresponding elongate vertical slots in the hitch member. The vertical slots each have an enlarged portion at their upper ends so as to receive the head of a respective headed pin and a narrower lower portion so as to receive the shank of the headed pin. Thus the headed pins, when properly installed with their shanks received in the narrow portions of their respective slots, effectively prevent fore and aft and sidewise relative movement between the hitch member and the mounting frame. A pin is then inserted through holes in both the hitch member and the mounting frame which are in line with one another thus preventing vertical movement between the hitch member and the mounting frame. For uncoupling, this last-mentioned pin is removed and the mounting frame in the cultivator attachment mounted thereon is lifted clear of the cultivator as a unit.