AbstractWe describe a family in which many persons have generalized joint laxity frequently complicated by dislocation of major joints. The condition is an autosomal dominant trait, with high penetrance. The disorder observed in this family and in others from the literature appears to be a specific syndrome that can be distinguished from other familial forms of joint laxity such as simple familial joint laxity and the Ehlers‐Danlos syndromes. It has been designated the familial joint instability syndrome.