We reviewed the radiologic and clinical outcomes of hip joints affected by multiple epiphyseal dysplasia in 40 patients. The average patient age was 9.6 years. All patients were followed up for an average of 7.2 years. No patient underwent surgical treatment. The variances of the center-edge angle and femoral head coverage had the greatest tendency to increase with conservative treatment and follow-up (P=0.011 and 0.015, respectively). The acetabular angle and the acetabular depth index at the first visit and the latest follow-up were statistically significantly different (P=0.046 and 0.027, respectively). According to the Stulberg classification, the severity of hip deformity became less severe with age, but this was not statistically significant (P=0.090). Larger improvements in Harris hip scores were identified after conservative treatment (P=0.003). Favorable midterm outcomes were obtained for the treatment of hip deformity in multiple epiphyseal dysplasia patients by conservative treatment.