This randomized control trial used intent-to-treat analyses to compare parent management training—Oregon model (PMTO) (N = 64) to family-based services as usual (SAU) (N = 62) in 3.5–13-year-old children and their families in Denmark. Outcomes were parent report of child internalizing and externalizing problems, parenting efficacy, parenting stress, parent sense of coherence, parent-report of life satisfaction, and parental depressive symptoms. Outcomes were measured at pretreatment, post-treatment, and 18–20 months post-treatment. Results demonstrated that both PMTO and family-based SAU resulted in significant improvements in child externalizing and internalizing problems, parenting efficacy, as well as parent-reported stress and depressive symptoms, life satisfaction, and aspects of sense of cohesion. Effect sizes at post-treatment and follow-up were in the small to moderate range, consistent with prior PMTO evaluations. However, there were no significant differences between PMTO and family-based SAU. Further research on the process and content of family-based SAU is needed to determine how this approach overlaps with and is distinct from PMTO.