This effectiveness study presents the results of a 1-year follow-up of a randomized controlled trial of Parent Management Training. Families of 112 Norwegian girls and boys with clinic-level conduct problems participated, and 75 (67%) families were retained at follow-up. Children ranged in age from 4 to 12 at intake (M = 8.44). Families randomized to the control group received an active treatment alternative as would be normally offered by participating agencies. Multi-informant, multisetting outcome measures were collected and results from both intention-to-treat and treatment-on-the-treated analyses are presented. In two separate indirect effects models, assignment to Parent Management Training-the Oregon model predicted greater effective discipline and family cohesion at postassessment, which in turn predicted improvements in several child domains at follow-up.