Myoglobinuria is still considered to be an uncommon occurrence, however, with the advent of better diagnostic tests it is being increasingly recognized as a potentially life-threatening complication of muscle necrosis. The pathologic consequences of myoglobinuria, including respiratory failure, hyperkalemia, and acute renal failure demand recognition by all who work in areas where this syndrome may develop. This article describes the role of myoglobin in the muscle and how myoglobinuria may develop. It includes the symptoms, differential diagnosis, and treatment of myoglobinuria and possible complications.