We report on a father and daughter in the second known family affected with F-syndrome. The first family, with 8 affected members, was reported by Grosse et al. [1969: BD:OAS V (3):48-63]. F-syndrome, an autosomal-dominant trait, is mainly characterized by acral defects that may also involve the sternum and the lumbosacral spine. Synostoses between capitate and hamate, and between talus and navicular, are invariably present; other carpal and tarsal bones are sometimes incorporated into the fusion. The hand malformation is principally a malformation of the first 2 rays. In our patients, the short and malformed thumb was webbed with the index finger, which was radially deviated with duplication of the middle and distal phalanges. In the feet, polydactyly and severe metatarsal and toe anomalies were present. The father had a prominent sternum with pectus excavatum, whereas the daughter had no sternal deformity. Both of them had a mild failure of fusion of posterior arch L5 and/or S1.