Stiff-man syndrome (SMS) is a rare disorder characterized by progressive rigidity, stiffness, and spasms of axial and extremity muscles. The etiology of SMS is unknown, but evidence suggests a possible autoimmune basis. The recent successful use of intravenous immunoglobulin (IVIG) in treating various autoimmune neuromuscular disorders led us to try IVIG in an uncontrolled pilot study on three patients. All three showed subjective and objective improvement.