Clinical and cytogenetic findings in a male infant with partial deletion of the short arms of a No. 4 chromosome are described. The clinical findings in the seven known cases (labeling studies have been done in five) were compared in relation to those in the cat cry syndrome. Features characteristic of the No. 4 deletion syndrome are an absence of cat-like cry, seizures, prominent glabella, midline scalp defects, deformities of the iris, cleft lip and palate or high-arched palate, preauricular dimple, misshapen nose, hypospadias in male infants, and hypoplasia of the dermal ridges. The No. 4 deletion syndrome is considered to be an entity distinct from the cat cry syndrome.