In this non comparative, open clinical study, 85 patients diagnosed as active osteoarthrosis (49 gonarthrosis, 36 lumbar spondylosis) were treated with 20 mg. oral single dose of tenoxicam, administered for 6 weeks. Results obtained at short periods as 3 weeks and 6 weeks were correlated with each other and also evaluated globally. Statistically significant (p < 0.001) improvement was demonstrated in parameters as spontaneous pain, pain on motion, pain after normal daily activity and functional capacity. Global clinical efficacy was found excellent to good or moderate in 80 patients (94.1%). Global tolerability was found excellent or good in 81 patients (95.4%). In 4 patients (4.6%) moderate side effects were noted but these were mild and transient. Tenoxicam is considered to be an efficient and secure therapeutic agent in the treatment of active osteoarthrosis.