A slowly progressive myopathy was discovered in a family in four successive generations. Eight patients (four female, four male) from three generations were examined and they showed muscle weakness affecting predominantly proximal, but also distal, muscles. Two patients had unequivocal findings in childhood, the others showed myopathy in their twenties or thirties. Working ability was lost in physically demanding jobs in the thirties, but activities of daily living were still preserved. Elbow contractures, tight heel cords and contractures of the interphalangeal joints were frequent. Serum CK activity was usually mildly elevated and electromyographic examinations revealed myopathic changes. Histopathological changes were compatible with moderately advanced muscular dystrophy in two patients, the six others had mild myopathic changes.