Youth referred to mentoring programs vary considerably in the range and severity of difficulties (i.e., behavioral, internalizing, social and academic) and environmental challenges they face. However, their patterns of risk and corresponding consequences for mentoring have rarely been investigated. This study draws on data for youth participants in 30 mentoring programs (n = 2,165, 55.1% females) to examine patterns of presenting challenges. Four profiles emerged using three-step latent profile analyses. Profiles with more intensive symptoms were associated with more environmental stressors. Moreover, there were significant differences between profiles in youth-perceived relationship attributes, including closeness, youth-centeredness, growth focus and mentor-mentee relational health. The profile with the highest externalizing and social challenge indicators scored the lowest across these four relational indices. The results highlight variability of youth risk at baseline, and its differential impact on mentoring relationship outcomes. Implications for mentoring programs are discussed.