1. Four cases of ochronotic arthropathy have been studied and the related literature has been reviewed.

2. Ochronotic arthropathy is a rare condition resulting from an inborn error of metabolism occurring as a Mendelian recessive characteristic. Its incidence, however, may have been underestimated.

3. Problems of differential diagnosis are discussed and it is suggested that more widespread screening should be undertaken in order to assess the true incidence of the condition.