ABSTRACT. Objective: Despite the increasing need to identify and implement effective interventions to reduce drinking with mandated college students, peer-led brief alcohol interventions have received minimal research attention. The current pilot study tested whether enhanced supervision (evidence-based application approach [EAA; group plus individual]) would improve peer counseling skills beyond those acquired by a common practice approach (CPA; group only). Method: Following initial peer counselor skill evaluation, drinking outcomes after intervention were compared between supervision groups with a mandated college student sample (N = 82; 65 men). The relationship between acquired motivational interviewing skills and subsequent drinking behaviors was also assessed. Results: EAA peer counselors showed higher motivational interviewing skill acquisition than CPA peer counselors. Despite differences in counselor skill demonstration, mandated clients in both intervention groups signifi cantly reduced drinking behaviors. Further, higher refl ection-to-question ratio and motivational interviewing spirit demonstrated by peer counselors were signifi cantly related to poorer follow-up drinking outcomes. Conclusions: Findings identify supervision practices that may result in optimal peer counselor learning and brief intervention implementation while also offering initial data about the way in which peer counseling session implementation may relate to drinking outcomes. Future research is needed to identify the within-session processes of peer-led interventions that predict drinking outcomes, which may offer additional direction for training approaches. (J. Stud. Alcohol Drugs, 75, 458-466, 2014) Received : February 22, 2013. Revision: October 8, 2013. Nadine Mastroleo's contribution to this article was supported by National Institute on Alcohol Abuse and Alcoholism (NIAAA) Grant T32 AA07459 and the Brown University Center for Alcohol and Addiction Studies Research Excellence Award. Molly Magill's contribution to this article was supported by NIAAA Grant K23 AA018126. Brian Borsari's contribution to this article was supported by NIAAA Grants R01 AA015518 and R01 AA017874. The contents of this article do not represent the views of NIAAA, the Department of Veterans Affairs, or the United States Government. *Correspondence may be sent to Nadine R. Mastroleo at the Center for Alcohol and Addiction Studies, Brown University, Box G-S121-5, Providence, RI 02912, or via email at: Nadine_Mastroleo@brown.edu. H AZARDOUS DRINKING among college students continues to be a signifi cant health concern (Dimeff et al., 1999;Hingson, 2010;Hingson et al., 2005;O'Malley and Johnston, 2002), with 18% of college students meeting the criteria for alcohol abuse or dependence (Dawson et al., 2004), and 40% of college men and approximately 30% of college women reporting at least one heavy drinking episode (fi ve or more alcoholic drinks in one sitting) within the past 2 weeks (American College Health Association, 2012). These heavy drinking epi...