Far more has been written about the possible outcomes of cross-age mentoring than about actual outcomes and the processes that lead to change. This study examined the effect of mentors' attendance on their mentees' outcomes after six months of developmental mentoring. Developmental mentoring is a structured, cross-age peer mentoring program designed to promote children's development by facilitating connectedness. In this randomized study of 73 Caucasian, rural youth, multiple analyses of covariance revealed that connectedness to school and parents at posttest were significantly greater for mentees than for the comparison group. Regression analyses revealed that changes in self-esteem, social skills, and behavioral competence were highly related to mentors' attendance, suggesting relational processes accounted for more change than did exposure to program curricula. However, the relationship between mentors' inconsistent attendance and mentees' decline in self-esteem and behavioral competence suggests that absent mentors may do more harm than good. © 2005 Wiley Periodicals, Inc. Psychol Schs 42: 65–77, 2005.