112 actively parachuting sport (free fall) parachutists with more than 200 descents each and 109 veteran military parachutists no longer active returned a postal questionnaire about their parachuting activities, injuries, and current and past musculoskeletal symptoms. A high frequency of fractures and injuries was reported by each group, both in relation to parachuting and to other activities. 58 sport parachutists aged 23 to 57 years (mean 33 - 3 years) had weight-bearing anteroposterior and lateral radiographs taken of each knee. These showed a prevalence of radiological osteoarthrosis of 10 - 4% which was mild in degree in all but one knee in one subject. 46 ex-military parachutists aged 50 to 70 years (mean 55 - 2 years) had weight-bearing anteroposterior radiographs taken of both knees and showed a prevalence of radiological osteroarthrosis of 41 - 3%. Moderate and severe changes were found in 10 - 9%. In both groups of parachutists six of the eight knee joints showing either moderate or severe radiological osteroarthrosis had been subjected to a previous meniscectomy. Forty ex-military parachutists had anteroposterior radiographs of the ankles (talotibial articulation) and showed a prevalence of osteoarthrosis of 17 - 5%, with the majority showing mild changes. There was a poor correlation between radiological osteoarthrosis, ankle symptoms, and previous fractures. With the reservation that the great majority of the sport group are still young (95% aged less than 50 years), it is concluded that parachutists as a group do not show an increased prevalence of radiological osteoarthrosis of the knee or ankle.