A case of bilateral synovial osteochondromatosis in a patient with hereditary arthro-ophthalmopathy is presented. The osteochondral lesions were largely calcified in one joint and largely chondromatous in the other. Typical features of hereditary arthro-ophthalmopathy are reviewed and it is hypothesised that the abnormal collagen in this syndrome is responsible for the development of synovial osteochondromatosis. Synovial manifestations of skeletal dysplasias have to our knowledge not been described previously but we suggest that synovial osteochondromatosis can be the manifestation of an underlying skeletal dysplasia.