Using official school data, this study examined a sample of 447 at-risk students enrolled over a 10-year period in a youth-based mentoring program. The primary objective of the program was to ensure high school graduation. Participants were identified by indices of academic and school behaviors that rendered them less likely to graduate from high school. This study used logistic regression to examine the extent to which academic (i.e., GPA, grade retention, and math and reading proficiency scores) and behavioral (i.e., expulsions) variables, as well as age at entry of program, and duration in the program predicted high school graduation. Results indicated that GPA and participants' age at time of enrollment in the program were significant predictors of graduating high school. Implications are drawn for designers of diversion, intervention, and mentoring programs. (Contains 5 tables.)