The paper reports the results obtained in a study on the frequency of fractures in patients affected with Duchenne Muscular Dystrophy and Spinal Muscular Atrophy, types II and type III; the patients were observed between 1974 and 1988 at the muscle clinic of the Rizzoli Orthopaedic Institute. Out of a total of 238 cases, 36 (15.1%) reported one or more fractures during the follow-up period. For each fracture, age, functional capacity, the particular circumstances in which fractures occurred, site and type of fracture, medical treatment and consequences were all considered. A protocol for fracture prevention in neuromuscular patients is proposed, and suitable methods of treatment suggested.