Background: Preliminary evidence indicates that fetal drug exposure may be associated with alterations in temperament. However, studies often do not dissociate the potential effects of drug exposure from other perinatal or environmental factors that could influence temperament phenotypes. Methods: High risk children (n = 120) were followed from birth to 6 months of age to determine the effects of fetal drug exposure on temperament, after controlling for the child's gender, gestational age, medical morbidity, ethnicity, and maltreatment as well as the mother's stress, income adequacy, and quality of caregiving. Methods included medical chart review, questionnaires, and videotapes of mother-child interaction. Results: Preliminary analyses indicated that fetal drug exposure was associated with both distractibility and intensity of children's responses to the environment at 6 months of age. After adjusting for potentially confounding variables, drug exposure accounted for 12% of the variance in distractibility but was not a significant predictor in the regression model for intensity. Conclusions: Findings suggest that drug-exposed children may experience difficulty sustaining their focus of attention and be more easily distracted by environmental stimuli than non-drug-exposed children. Results converge with previous research to implicate cortical hyperarousal, stemming from teratogenic effects on the dopaminergic system during fetal development.