Using a prospective, double blind, double dummy protocol, we compared the efficacy of subacromial injection of 40 mg of triamcinalone acetonide versus oral indomethacin, 100 mg/day, in 40 patients with acute rotator cuff tendinitis. Repeat injection and refill of medication was given after 3 weeks, if necessary. At 6 weeks, there was no significant difference between the 2 groups with respect to the percentage of patients who improved (60 vs 66%) or the magnitude of the change of pain and motion variables. This study suggests that there is essentially no difference in the short term efficacy of oral nonsteroidal therapy compared to local corticosteroid injection(s) in the treatment of rotator cuff tendinitis.