small size could not be explained by small parents, pulmonary vascular obstructive disease, profound failure to thrive in infancy, and intrauterine growth retardation may have caused their small size. The relation of intrauterine growth retardation and profound growth failure in infancy, and poor ultimate growth was observed by Levy and co-workers.8 The association between pulmonary vascular obstructive disease and small adult size was not reported previously. Patients in the operated group had a more marked growth response than did those in the nonoperated group, and all patients’ mean height and weight were similar as adults. “Catch-up” growth in operated patients during short and intermediate follow-up periods has been reported.ld The present study is the first to report patients followed to ultimate adult size. Time of operation, and presence of congestive heart failure in infancy did not independently influence adult size. Because these patients were observed in the 1960s and underwent operation “late,” it was gratifying to learn that most responded well to late operations. It remains to be learned whether operations in the lirst 2 years, which is a common practice currently, will have any independent effect on later size.