Two patients with triphalangeal thumbs-ectrodactyly syndrome are described. The first case is a 4-year-old female with triphalangeal thumbs, preaxial polydactyly with rudimentary polydactyly of the 3rd finger of the right hand and ectro-syndactyly of feet. Her stillborn sister had triphalangeal thumbs and ectrodactyly of feet. The mother has triphalangeal thumbs, brachy-syndactyly of the left foot and ectro-syndactyly of the right one. The maternal grandmother has syndactyly of 1st, 2nd, 3rd toes and hypoplasia of the 3rd toe on the right foot. The second case is sporadic and shows triphalangeal thumbs, preaxial polydactyly of the right hand and bilateral lobster-claw feet. Our observations confirm the variability of clinical expression and support the autosomal dominant inheritance of the syndrome.