Primary myoglobinuria, also known as idiopathic or paralytic myoglobinuria and recurrent rhabdomyolysis, is a rare disease, 56 cases having been reported to date in the medical literature (1, 2). It is to be differentiated from secondary myoglobinuria occurring following crush injuries (3), high voltage accidents (4), convulsions (5, 6), arterial occlusion (7), and epidemic Haff disease (8). It must also be differentiated from other disorders characterized by the passage of dark urine, such as the porphyrias, march hemoglobinuria, paroxysmal cold hemoglobinuria, paroxysmal nocturnal hemoglobinuria, and the various nephritides. A clinical picture similar to muscular dystrophy has been noted to occur