A total of 37 (52.9 percent) of the children were placed in kinship foster care, and 33 (47.1 percent) were placed in nonrelative foster care. Information for the study was obtained through face-to-face, structured interviews with the children and their primary caregivers. Foster parent disciplinary behavior was assessed with the Discipline Methods Assessment. Disciplinary measures coded as nonphysical, maladaptive punishment and physical punishment were identified as "harsh disciplinary practices." Each caregiver was assigned a harsh disciplinary-practices score based on a sum of their primary and secondary discipline responses. The study hypothesized that harsh discipline by foster parents would be associated with greater aggression by foster children. Harsh disciplinary responses by foster parents were associated with a greater likelihood of their children using multiple aggressive solutions to social problems portrayed in vignettes. With each increase in reported harsh disciplinary practice, there was an almost three-fold increase in a child's aggressive solutions to social problems. No significant difference was found between kinship and nonkinship foster children in level of aggression. These findings imply that the modification of foster parent disciplinary practices may help address the behavioral problems of some foster children. 2 tables, 1 figure, and 42 references