Identified children and young adolescents who engaged in parent-directed physical aggression from a sample of youths referred for outpatient therapy (N = 606, 151 girls, 455 boys); examined the frequency, severity, and characteristics of such behavior; and compared aggressive youths with nonaggressive youths across several domains of functioning. Twelve percent of the children and young adolescents in this clinical sample engaged in parent-directed aggression. Aggressive, compared to nonaggressive, youths had significantly increased oppositional behavior, lower frustration tolerance, less adaptability to stressful situations, and were more demanding of their parents. Aggressive children had families characterized by significantly greater parental stress, poorer interpersonal relationships, and were more likely to be 2-parent, European American families of higher socioeconomic status. Moreover, lower frustration tolerance and adaptability were significant predictors of parent-directed aggression after controlling for demographic differences and overall level of oppositionality and aggressiveness, suggesting a more specific functional impairment in such children. Parent-directed aggression warrants additional study given the limitations in our understanding of these events and the potential for such behaviors to continue into adolescence and adulthood.