To determine the effects of prenatal cocaine exposure on intrauterine growth and neurologic function, 30 term infants were evaluated prospectively: 14 cocaine-exposed and 16 unexposed. Cocaine-exposed infants had significantly lower mean birth weights, birth lengths, and head circumferences than urine-negative controls. Neurologic abnormalities among cocaine-exposed newborns included hypertonia of any type (86% vs 33%), axial hypertonia (79% vs 19%), plantar extension (46% vs 19%), and coarse tremor (57% vs 12%). The degree of hypertonia was sufficiently severe to warrant a diagnosis of "hypertonic tetraparesis" in 64% of cocaine-exposed and 12% of unexposed infants (P = .007). This diagnosis was highly correlated to small head size (r = 0.48; P = .01). Persistent tonic downward gaze was evident in two neurologically abnormal cocaine-exposed newborns. Gaze abnormalities improved slightly over the next 3 weeks of observation. One such infant re-evaluated at 6 months of age revealed resolution of tonic downward gaze and neurologic findings. We conclude that prenatal cocaine exposure is associated with tone and movement abnormalities in newborn infants.