This study assessed the feasibility of a randomized controlled trial to evaluate the Big Brothers Big Sisters (BBBS) community match programs at the national level. Following a standardized protocol, 71 intake families (parents and children ages 7-14 years) and 30 adult mentors were recruited over 12 months from two BBBS agencies. Families were randomly assigned to the BBBS program (n=39) or a waiting list control (n=32). Information on children’s behavior and psychosocial outcomes was obtained from children and parents using face-to-face interviews and questionnaires administered after enrolling in the study (but prior to knowledge of assigned condition) and at 12 months follow-up. Tests of equivalence revealed nonsignificant group differences on most baseline outcomes. Twelve families dropped out prior to the post-test assessment. ANCOVA results revealed beneficial program effects for five outcomes (child self-reports): Symptoms of emotional problems, symptoms of social anxiety (fear of negative peer evaluations and generalized social anxiety and distress), teacher social support, and social skills (self-control). The study demonstrated the feasibility of an RCT to evaluate the BBBS programs. However, the design may be challenged ethically given the evidence of positive benefits and the requirement that control group children remain unmatched for a minimum of 12 months.