Background: effective and brief weight loss programs are needed for underserved (low-income, ethnic minority) populations; therefore, this study evaluated a novel motivational and parenting weight loss intervention that targeted underserved families.Methods: this pilot study employed a prospective randomized test of a brief family-based weight loss program to assess feasibility and changes in health outcomes. twenty families each with an overweight adolescent (mean age = 12.9 ± 1.4; 70% female, mean bMi = 33.7 ± 5.3 and bMi percentile = 98.5 ± 1.5; 65% African American) participated in the study. Families were randomized to either a motivational plus family weight loss intervention (M + FWL) or a basic health (bH) education program consisting of 6 weekly group sessions. this study assessed changes from baseline to 6-week post intervention in adolescent bMi, bMi z-score, dietary variables measured with three 24-hr food recalls, autonomous motivation for physical activity and diet, and positive parenting variables.Results: Adolescents in the M + FWL intervention significantly improved their intake of daily fruit servings (p < 0.05), motivation for diet (p < 0.01), and physical activity (p < 0.05) compared with the bH group. there was also a trend toward greater reduction in adolescent bMi z-score (p = 0.08), and total fat intake (p < 0.06). the M + FWL intervention exhibited high attendance rates (>90%) and participant satisfaction ratings.Conclusion: this 6-week program demonstrated high retention rates and improvements in adolescent health behaviors, providing preliminary support for a brief motivational and parenting weight loss program for underserved families.