This study was designed to obtain information concerning the general efficacy of out-patient physiotherapy for knee osteoarthritis, a disabling disease affecting approximately 1% of the population. Efficacy was initially studied retrospectively by reviewing the medical records of 26 Canadian out-patients. Then a six-month follow-up telephone survey was conducted on 14 of these patients (eight men and six women), mean age 59.2 years (range 24–77) who had received an average of 15.8 treatments including exercise (85.7%), education (42.8%), electrotherapy (35.7%), ice/heat (35.7%), and manual therapy (28.5%). The results showed initial objective improvements in knee strength in 47% of cases; reduced knee pain levels in 76% of cases; and improvements in knee range of motion in 53% of cases. At the six-month follow-up 79% of the patients interviewed had maintained improvement in stair climbing, level walking and sit-to-stand activities. It is concluded that a high proportion of patients with moderate to severe knee joint disease may experience continued functional benefits from relatively brief out-patient physiotherapy programmes, despite the poor outlook often associated with the disease. This study was designed to obtain information concerning the general efficacy of out-patient physiotherapy for knee osteoarthritis, a disabling disease affecting approximately 1% of the population. Efficacy was initially studied retrospectively by reviewing the medical records of 26 Canadian out-patients. Then a six-month follow-up telephone survey was conducted on 14 of these patients (eight men and six women), mean age 59.2 years (range 24–77) who had received an average of 15.8 treatments including exercise (85.7%), education (42.8%), electrotherapy (35.7%), ice/heat (35.7%), and manual therapy (28.5%). The results showed initial objective improvements in knee strength in 47% of cases; reduced knee pain levels in 76% of cases; and improvements in knee range of motion in 53% of cases. At the six-month follow-up 79% of the patients interviewed had maintained improvement in stair climbing, level walking and sit-to-stand activities. It is concluded that a high proportion of patients with moderate to severe knee joint disease may experience continued functional benefits from relatively brief out-patient physiotherapy programmes, despite the poor outlook often associated with the disease.