Abstract: An automatic control system (3) for the handles (B) of plastic bags disposed in stacks (M) is described, including a video camera (30) adapted to capture the image of the stack (M) of bags in the position of the handles (B) and an image processing system which converts the pixels acquired by the video camera (3) into geometric outlines of the handles which can thus be measured to see if the handles (B) of the stack come within the pre-set range of tolerance. The control device (3) further checks that die cutting has taken place correctly, that is, that the entire scrap, which may have remained attached at a single point, has been removed. The control device (3) further employs a system of side guides (80) for the film (P) placed in the sealing unit (100) for formation of the bags, adapted to reduce lateral shifting of the film (F) during processing, thus reducing the final waste of product due to out-of-range handles (B).