Tested the hypothesis that minor physical anomalies (MPAs) modify an adolescent's vulnerability to environmental risk factors for psychopathology. 118 male 17-yr-olds who had been evaluated as 7-year-olds received a comprehensive neuropsychiatric evaluation. The evaluation included standardized assessments of environmental risk factors for psychiatric impairment, neurological signs, IQ, MPAs, and psychiatric impairment. The relationship between psychiatric status and environmental risk was examined as a function of the MPA profile. There was a significant interaction between MPAs and environmental risk in predicting psychiatric status. Environmental risk was more predictive of psychiatric impairment at age 17 in Ss with high scores on the MPA scale than in Ss with low scores on the scale. This relationship was particularly apparent in Ss with conduct disorder. MPAs also exhibited relationships with 2 childhood factors, neurological soft signs and Verbal IQ, that had been shown to predict adolescent psychopathology in prior reports on this cohort.