This study evaluates the perinatal outcome of infants born to ninety-five mothers with hypertension in pregnancy whose blood pressure was treated in a double blind trial comparing clonidine hydrochloride (C) and alpha-methyldopa (A). There were no fetal deaths and two neonatal deaths, giving a perinatal mortality of 2%. There was no significant difference between Groups C and A with regard to the gestation or weight at birth, incidence of intrauterine growth retardation, or condition at birth as judged by Apgar scores and acid-base status. No infant in either group developed significant hypotension or rebound hypertension. The blood pressure was not significantly different between Groups C and A, and controls. In each of these three groups there was a similar significant rise in systolic blood pressure with age.