Thirty patients presenting with painful shoulder syndrome were treated with i.m. ketoprofen 100 mg b.d. for 8 days to assess the efficacy and tolerance of the above treatment regime. The patients' condition was monitored by clinical, instrumental and laboratory examinations. Ketoprofen was found to be significantly effective in all cases of non calcific rotator cuff tendinitis while no improvement was noted in calcific tendinitis. The above data confirm the efficacy and tolerance of ketoprofen in the treatment of painful shoulder syndrome as an alternative to local steroid therapy.