Newborn infants with wide cranial sutures and large anterior fontanels, but having normal head circumferences, were prospectively studied and compared with a group of normal controls. The study group with wide sutures was composed of two different groups--one with good calcification of the calvaria, fairly large anterior fontanels, and no Wormian bones; and another with distinct parietal prominences, very large anterior and posterior fontanels with prolonged patency, poor initial calcification of the calvaria, and Wormian bones. Normal head growth and physical and mental development were observed in all the infants studied.