Abstract: In a method for automatically gutting fish of the catfish species, the belly cavity is opened around the anal orifice either before or after opening the gills by severing the gullet and opening the blood stream, and the contents of the belly cavity are removed by pushing these from one of the openings of the cavity out of the other. In a machine for carrying out this method, the fish are conveyed sideways by a recessed conveyor. The belly cavity is opened in the vicinity of the anus by separating away the cartilaginous plate carrying the ventral fins. The contents of the ventral cavity are removed by a rotary body rotating synchronously with the conveyor and having tools successively arranged in a cantilevered helix around its circumference which comprise a clearing tool with scraping segments, a brush tool, a high-pressure spray device and a cutting tool for slitting open the belly cavity along its length.