Convulsive shock therapy has been employed for several years in the treatment of severe psychoses without sufficient attention being paid to undesirable complications.1We are reporting seven cases of spontaneous fractures which have occurred during the convulsions induced by metrazol (pentamethylenetetrazol). We shall also suggest a procedure for preventing most of these catastrophes. Lehndorff1awas the first to report fractures resulting from the severe muscular contractions associated with tetanus. Later Sonntag2reported fractures of the elbow and dislocations of the shoulder, Baisch3discussed fractures of the femoral neck and Wilhelm4described fractures of the forearm. All these fractures occurred during tonic convulsive seizures of tetanus. Roberg5made a comprehensive study of the spinal changes and concluded that the forces exerted by tetanic muscular contractions produced compression fractures of the midthoracic vertebral bodies, usually those of the fifth and sixth vertebrae, in definite contrast to