Caffeine (from coffee, tea, cola, and/or chocolate) was the most frequently ingested drug among 1529 pregnant women interviewed in 1974-75. Linear and threshold effects of prenatal caffeine on pregnancy outcome and offspring development were examined in a cohort of approximately 500 offspring. After appropriate statistical adjustment for relevant covariates (cigarette smoking, alcohol, maternal size, demographics, etc.) prenatal caffeine exposure was not related to most newborn and infant outcome measures, including height, weight or head circumference, or to individually administered IQ and attention tests at 7 years of age. Only one isolated dependent variable of the many was significantly associated with prenatal caffeine exposure: namely breech presentation. However, since this report involved a secondary analysis of data gathered for other purposes, specifically designed studies would be required to determine the validity of the observed association for any particular variable. The general conclusion is that the long-term consequences of prenatal caffeine in this cohort are null.