Clinic mothers of 35 conduct-disordered children were randomly assigned to a waiting list control group, 9 weeks of individual therapy, or 9 weeks of therapist-led group therapy based on a standardized videotape modeling program. Mothers and their children were assessed at baseline, immediately after treatment, and 1 year later by home visits, twice-per-week telephone reports, and questionnaires. One month after treatment, both groups of treated mothers showed significant attitudinal and behavioral improvements compared with untreated controls. Additionally, the children in the two treatment groups showed reductions in child noncompliance compared with control children. At the 1-year follow-up, not only were most of the changes in mothers? behaviors maintained, but both treatment groups of children continued to show significant reductions in noncompliant and deviant behaviors. There were no significant differences on any of the attitudinal or behavioral measures between individual and videotape modeling group discussion therapies at the immediate or 1-year follow-up. Total therapist time was approximately 251 hr for the entire individual group and 48 hr for the entire videotape discussion group. Although both treatments seem to offer equivalent and sustained improvements for parents and conduct-disordered children, the therapeutic efficiency of the videotape modeling group format is more cost-effective.?