A solution is proposed for unloading bookbinding items (305) into stacks (310). A corresponding unloading system (130;430) comprises a sequence of stackers (135a-135c;435a-435c). Each stacker following the first one (135b-135c;435b-435c) comprises a stacking zone (215) for stacking the bookbinding items (305) supplied by a corresponding bookbinding machine (105a-105c;405a-405c) above a transit zone (205) of corresponding stacks (310), thereby not interfering with their transit. A bookbinding system (100;400) comprising this unloading system (130;430) is also proposed. A corresponding method (700) for collecting bookbinding items (305) into stacks (310) is proposed. The unloading system further comprises: condition detectors (225), transit conveyors (145ab-145bc), stop elements (230), presence detectors (235), and an unloading conveyor (145c).