Prenatal cocaine exposure has been associated with behavior problems at school age. However, the correspondence between use of cocaine and alcohol during pregnancy is often high, making appropriate allocation of variance and control for other exposures and their interactions difficult. Additionally, gender-specific effects are not typically reported. The purpose of the current study was to determine the degree to which gender-specific effects of prenatal cocaine exposure on teacher-reported child externalizing behavior problems were evident when evaluated in relation to prenatal alcohol exposure. Subjects were singleton infants of mothers who were prospectively evaluated during pregnancy. At age seven, 499 children (214 exposed prenatally to cocaine) were evaluated in our laboratory and teacher reports were solicited. Analyses stratified by gender and prenatal alcohol exposure status, and controlled for significant pre- and postnatal confounders, revealed that among boys with prenatal alcohol exposure, those with persistent cocaine exposure throughout pregnancy had significantly higher levels of Delinquent Behavior compared to boys with no cocaine exposure. Boys with any prenatal cocaine exposure were twice as likely as unexposed boys to have clinically significant Externalizing Behavior scores. However, no association was found between prenatal cocaine exposure and scores on Externalizing Behavior and specific syndromes for boys with no prenatal alcohol exposure. Among girls with no prenatal alcohol exposure, those with persistent cocaine exposure had significantly higher levels of Externalizing Behaviors and Aggressive Behaviors compared to girls with no prenatal cocaine exposure after control for confounding, and were almost five times as likely to have clinically significant Externalizing Behavior scores. However, for girls with prenatal alcohol exposure, no association between prenatal cocaine exposure and scores on Externalizing Behavior and specific syndromes was found after control for confounding. The current findings support gender- and alcohol-moderated effects of prenatal cocaine exposure on school-age teacher-reported child behavior problems. These findings are similar to what we have reported for independent parent-reported behavioral evaluation.