Two cases are reported of familial partial trisomy 6q syndrome due to segregation of ins(5;6) (q33;q15q27) in three generations. The common clinical features include growth and mental retardation, feeding difficulty during infancy, microcephaly with downward slanting palpebral fissures, flattened nasal bridge with anteverted and flared nares, long philtrum, high arched palate, partially opened and protruding mouth with receding chin, deep transverse creases of the ears, three creases on the 4th fingers, clinodactyly of the 5th fingers with a single crease, and other dermatoglyphic findings. These characteristic features of two patients appear to make partial trisomy 6q a clinically recognizable syndrome.