A sizable proportion of term infants in India are small for date. Intrauterine growth retardation has been attributed to suboptimal placental function. An investigation was undertaken to determine whether differences in the chemical composition of the placenta could be related to the birth weight of infants. Placentas of pregnancies with small-for-date infants were found to be smaller in size and to have lower amounts of nitrogen, deoxyribonucleic acid, and ribonucleic acid as compared to placentas of normal pregnancies. Also, the glycogen content was lower, but its rate of utilization was higher in placentas of pregnancies with small-for-date infants. Heat-stable alkaline phosphatase concentration was also low. These observations suggest that in placentas of pregnancies with small-for-date infants there is an acceleration of the aging process which may have functional significance.