A previously unreported case of congenital contractural arachnodactyly (CCA) is described. This hereditary connective tissue abnormality resembles Marfan's syndrome in certain respects, but is characterized by camptodactyly rather than joint laxity, as well as by congenital contractural deformities of the knees and elbows. In addition, there is a peculiar, fairly characteristic deformity of the external ear. Like Marfan's syndrome, it is transmitted in autosomal dominant fashion. Despite the superficial skeletal resemblance, however, the cardiovascular and ocular complications of Marfan's do not seem to occur and therefore differentiation of the two syndromes is important.