This study evaluated the effects of problem-solving skills training (PSST) and parent management training (PMT) on children (JV = 97, ages 7-13 years) referred for severe antisocial behavior. Children and families were assigned randomly to 1 of 3 conditions: PSST, PMT, or PSST and PMT combined. It was predicted that (a) each treatment would improve child functioning (reduce overall deviance and aggressive, antisocial, and delinquent behavior, and increase prosocial competence); and (b) PSST and PMT combined would lead to more marked, pervasive, and durable changes in child functioning and greater changes in parent functioning (parental stress, depression, and overall symptoms). Expectations were supported by results at posttreatment and 1-year follow-up. PSST and PMT combined led to more marked changes in child and parent functioning and placed a greater proportion of youth within the range of nonclinic (normative) levels of functioning. Antisocial child behavior includes aggressive acts, theft, vandalism, fire setting, lying, truancy, running away, and other acts that violate major social rules and expectations. A persistent pattern of antisocial behavior, referred to as conduct disorder, affects diverse domains of current functioning and for many youth portends continued dysfunction in adulthood (see Robins, 1981; Rutter & Giller, 1983). Several characteristics underscore the clinical and social significance of conduct disorder. The prevalence rate is relatively high and encompasses 2 to 6% of school-age children (Institute of Medicine [IOM], 1989). In the United States alone, this translates to between 1.3 and 1.8 million cases. In addition, among children and adolescents, conduct disorder and aggressive and antisocial behaviors encompass one half to one third of all clinic referrals and lead the list of dysfunctions seen in clinical practice (see Kazdin, 1987a). Several longitudinal studies indicate that conduct disorder is relatively stable over time, portends diverse problems in adulthood (e.g., criminal behavior, alcoholism, and poor work adjustment), and often continues across generations (see Pepler & Rubin, 1991; Robins & Rutter, 1990). Among the challenges to treatment is the range of dysfunctions that antisocial youth display. In addition to their antisocial symptoms, youth often evince hyperactivity, cognitive deficits and distortions, poor peer relations, and academic dysfunc