The relationship between long-term ballet dancing and eventual arthrosis of the hip, ankle, subtalar, and first metatarsophalangeal joint was examined in 19 former professional female dancers, aged 50 to 70 years. The dancers were compared with pair-matched controls. All 38 women underwent medical history taking, clinical examination, and roentgenography of the joints studied. The roentgenographs were independently judged by two investigators and grouped according to a modified classification of Hermodsson. We found a statistically significant increase in roentgenologic arthrosis of the ankle, subtalar, and first metatarsophalangeal joints in the ballet group compared with the control group. There was no significant difference regarding degenerative changes of the hip joint. However, subjects in the dance group who had evidence of degenerative changes on roentgenographs had no clinical complaints. There was a statistically significant increase in hallux valgus deformity in the ballet group (P < 0.05). The dancers also showed a statistically significant increase in flexion, external rotation, and abduction of the hip joint, dorsal flexion of the first metatarsophalangeal joint, and inversion and eversion of subtalar joint. But the control group had statistically significant increased plantar flexion of the first metatarsophalangeal joint. The most important cause of the statistically significant increase of arthrosis of the ankle and first metatarsophalangeal joints must be explained by repetitive microtrauma.