Literature on retention focuses on both short term and long term outcomes for retained students. Short term outcomes typically include academic achievement, self-esteem issues, and occurrence of behavior problems. Long term outcomes include academic growth and persistence to graduation. Regardless of the focus and intent of the study, research on retention is characterized by conflicting conclusions. Longitudinal research is a particularly important methodology for studying retention because it allows the researcher to understand how the effects of retention change or persist over time (Tanner and Galis, 1997). Longitudinal literature on retention focuses on a cohort of retained students and their long-term outcomes such as academic achievement, self-esteem, and dropping out of school. A cohort of retained students is typically matched by same grade or same age with promoted students. This analysis of longitudinal literature is organized to discuss those studies that show negative outcomes for students and studies showing positive student outcomes. This paper also highlights the interesting longitudinal work on retention that has come out of Chicago and Texas.