Recent research has found that the dopamine D4 receptor (DRD4) gene and maternal insensitivity may interact to predict externalizing behavior in preschoolers. The current study attempted to replicate and extend this finding in a sample of 18–30-month-old children. The current study examined two distinct dimensions of parenting (warm-responsive and negative-intrusive) as predictors of childhood externalizing and internalizing behavior. Further, race was investigated as a moderator of gene–environment relationships. Results revealed that high warm-responsive parenting was associated with decreased externalizing behavior only for African American children possessing the short polymorphism of DRD4. The data indicate that children may be differentially susceptible to different aspects of parenting depending on their genotype, and it is important to consider differences in racial composition when studying these relationships. © 2007 Wiley Periodicals, Inc. Dev Psychobiol 49: 619-632, 2007.