Several psychosocial, family-focused evidence-based treatments (EBTs) for youth with disruptive behavior have proven effective in practice settings. However, limited research has examined community implementation of EBTs for pediatric depression and bipolar disorder. This pilot open trial evaluated multi-family psychoeducational psychotherapy (MF-PEP) with 41 children ages 7 to 12 (54% male, 92% Caucasian) with mood disorders and their parents in an outpatient setting. MF-PEP is an 8-session, adjunctive EBT with parallel child and parent groups. Fourteen community therapists facilitated 6 MF-PEP groups at 3 agencies over 2 years. Developed checklists were used to evaluate adherence. Clinical outcomes were measured via clinician assessment and self-report questionnaires at pretreatment, posttreatment, 6-month follow-up, and 12-month follow-up, and analyzed via hierarchical linear modeling. Therapist group adherence ranged from 66.71% to 78.68% (M = 72.14%, SD = 4.85). Children experienced significant improvement in depressive and manic symptoms, and parents reported a significant increase in knowledge of mood disorders. Children with bipolar disorder and families with limited treatment history benefitted most from MF-PEP. Effect sizes (Cohen’s d) ranged from small to large for mood outcomes (d = 0.34 to 1.18), knowledge (d = 1.02), and treatment beliefs (d = 0.04 to 0.41). Limitations included small sample, missing data, and open design. Results suggest that MF-PEP may be impactful for families affected by pediatric mood disorders in the community, especially among youth with bipolar disorder and families novice to treatment. Randomized controlled trials are needed to provide more definitive evidence for the effectiveness of MF-PEP in practice settings.