The authors report a case of a premature infant with unusually high concentrations of transplacentally acquired caffeine. The mother drank 24 cups of coffee per day during pregnancy. The infant developed apnea, and not having known the above maternal history, was started on caffeine therapy. Serum caffeine concentration was found to be 40.3 micrograms/ml prior to caffeine administration on the fifth day of age. Caffeine concentration at birth was probably much higher based on the pharmacokinetic extrapolation (caffeine half-life of 100 hours). It is suggested that manifestation of apnea in this infant may have been related to caffeine withdrawal.