Some children are more affected by specific family environments than others, as a function of differences in their genetic make-up. However, longitudinal follow-up studies of genetic moderation of parenting effects during early childhood have not been conducted. We examined developmental profiles of child behavior problems between 18 months and age 8 in a longitudinal parent-offspring sample of 361 adopted children. In toddlerhood (18 months), structured parenting was observed during a home visit. Biological parent psychopathology served as an index of genetic influences on children’s behavior problems. Four profiles of child behavior problems were identified: low stable (11%), medium stable (50%), high stable (29%), and high increasing (11%). A multi-nominal logistic regression analysis indicated a genetically moderated effect of structured parenting, such that for children whose biological mother had higher psychopathology, the odds of the child being in the low stable group increased as structured parenting increased. Conversely, for children whose biological mother had lower psychopathology, the odds of being in the low stable group was reduced when structured parenting increased. Results suggest that increasing structured parenting may be a salient and modifiable intervention approach during toddlerhood, but only for children at higher genetic risk for psychopathology.