Abstract: Machine for compacting fuel assemblies, constituted by protective structures containing the fuel and carrying caps at their ends, and for separating the caps from said structures, wherein it comprises a frame forming a lateral bearing surface, a compacting slide block forming a lateral bearing surface facing the first-mentioned bearing surface, a feed opening formed in the frame for introducing an assembly between these surfaces, means for displacing the slide block in a direction perpendicular to these surfaces, two cutting members carried by the slide block and respectively facing the two discharge openings for the caps formed in the frame at the ends of the bearing surface formed thereon, means for displacing the cutting members in said direction in order to separate the caps from the structures, and means for discharging the compacted structure to a discharge opening for the same, formed in the frame.