This study explores the association between a supplemental instruction (SI) program and student performance in an introductory accounting course. SI is a proactive academic support program that is aimed at improving student learning in traditionally "high-risk" college courses by integrating learning and critical thinking strategies with technical course content. This paper examines and describes the classical SI model as it has been applied in both non-business and business disciplines. We then extend the work of Etter, Burmeister, and Elder (2000) and Jones and Fields (2001) which examine the effectiveness of the SI model in introductory accounting by providing empirical tests after controlling for differences in SI group leaders. The SI leader's duty is to provide structure to the collaborative learning environment and to integrate study skills and learning strategies with course content. However, empirical analysis incorporating controls for differences in SI leaders is lacking. Results, based on both nonparametric chi-square analysis and analysis of covariance (ANCOVA) indicate that SI is an effective program that increases academic performance as measured by total points earned in the course. Further, results suggest that the SI program remains effective across multiple SI leaders.