The authors examined the effects of the type of mentoring relationship and the gender composition of the relationship on mentoring functions and career outcomes reported by 352 female and 257 male proteges. Proteges of informal mentors viewed their mentors as more effective and received greater compensation than proteges of formal mentors. Proteges with informal mentors also received more career outcomes than nonmentored individuals, but no significant differences were found between nonmentored and formally mentored individuals. The gender composition of the relationship affected mentoring functions and outcomes, and protege gender interacted with the type of relationship to affect mentoring functions.