1. Seven cases of haemophiliac arthropathy of the hip joint are reported.

2. Attention is drawn to the different appearances in the hip when it is affected before and after puberty. Before puberty there are features similar to pseudocoxalgia. After puberty there may be cyst formation, coxa valga, or features similar to osteoarthritis.

3. It is suggested that intra-osseous haemorrhage is important in the production of these changes and that intra-epiphysial haemorrhage is responsible for the appearances seen before puberty.