The outcome of 636 pregnancies occurring to girls aged 14 or less in the years 1936-1960 has been analyzed. A higher incidence of toxemia, contracted pelvis, prematurity, immaturity, and perinatal mortality than is contained in reports in the literature was found. The size of the problem in an Eastern seaboard city was studied by the use of Baltimore City Health Department data. The conclusion is reached that in the study of pregnancy outcome in very young girls one should guard against dilution of statistics pertaining to the very young, by data pertaining to those in their later teens.