Adverse neonatal outcomes have been associated with intrauterine exposure to polychlorinated biphenyls (PCBs). In a follow-up study of exposed and nonexposed infants, 123 infants tested at birth were administered Fagan's test of visual recognition memory at 7 months. 2 measures of prenatal PCB exposure, cord serum PCB level and maternal report of contaminated fish consumption, both predicted less preference for a novel stimulus. Preference for novelty decreased in a dose-dependent fashion with increasing levels of prenatal PCB exposure. Postnatal exposure from nursing was not related to visual recognition memory. The relation between prenatal exposure and visual recognition was not mediated by the neonatal deficits, suggesting that intrauterine PCB exposure may have a delayed effect on central nervous system (CNS) functioning.