Supplemental Instruction (SI), a higher-education academic support program, targets challenging college courses and uses peer-led review sessions to develop academic skills, improve grades, influence persistence, and ultimately increase student retention (Arendale, 2001). The goals of this study were twofold: to determine if differences existed in prior academic performance of freshman students attending SI sessions while determining whether SI attendance improved retention to the sophomore year. Using quantitative analysis, the researchers found that freshman students with a higher high school GPA were more likely to be retained regardless of SI session attendance. Additionally, freshman students with a lower high school GPA were significantly more likely to be retained if participating in SI sessions. The researchers conclude that SI is an effective program to develop academic skills and yield increased retention. Implications for the profession include a renewed emphasis on increasing SI attendance rate of college freshman students, particularly at-risk students with lower college entrance credentials.