Acute sarcoid myositis is rarely complicated by sarcoidosis, and steroid therapy is considered the standard treatment. We experienced a patient with acute sarcoid myositis who did not respond to aggressive high-dose corticosteroid therapy, but showed a dramatic improvement after the addition of weekly low-dose oral methotrexate (MTX). This intervention allowed the resumption of normal daily activities after 6 months. Our case strongly suggests that MTX should be considered in patients with acute sarcoid myositis that is resistant to corticosteroid therapy.