Endings in youth mentoring relationships have received little empirical attention despite the fact that many relationships do end. The present study utilized qualitative interview data collected from participants in a longitudinal study of community-based mentoring relationships to examine how and why the relationships ended and how participants experienced these endings. Interviews with 48 pairs of mentors and youth and the youth’s parent or guardian conducted at the time the mentoring relationship ended were analyzed. Three types of procedural endings (formal goodbye planned and completed, formal goodbye planned but not completed, and agency ended) were identified as were five main reasons for relationship endings (changes in life circumstances, youth dissatisfaction or disinterest, mentor dissatisfaction, gradual dissolution, and mentor abandonment). Interrelationships between ending types and reasons are discussed, as are the roles of relationship strength and program support in these processes.