We assessed 57 total hip arthroplasties in 34 adolescents with juvenile chronic arthritis using standard radiological techniques at an average of 4.7 years (20 months to 9 years) after surgery. The incidence of overall loosening was 24.6% (14 hips), but hips with a follow-up of more than five years had a loosening rate of 43.5% (10 hips; p < 0.01).