SUMMARYIn a double-blind, cross-over study of 90 patients with degenerative disease of the hip, knee, cervical or lumbar spine, and capsulitis of the shoulder the analgesic drug benorylate (either alone or in combination with chlormezanone, a muscle relaxant anxiolytic drug) favourably modified pain, stiffness, quality of sleep and ability to work. Chlormezanone significantly reduced the number of breaks in sleep.There was no significant difference in the number of patients reporting side-effects on each of the four treatments, but drowsiness occurred significantly more in the chlormezanone weeks.There appeared to be no advantage in adding chlormezanone in patients suffering from osteoarthritis of the hip or knee, lumbar spondylosis or capsulitis of the shoulder, but there was significant improvement in both pain relief and quality of sleep in those patients with neck pain.