Although estimates are that only about half of youth mentoring relationships established through formal programs last beyond a few months, almost no attention has been paid to understanding mentoring relationship failures. In-depth semistructured interviews were conducted with 20 adult and 11 adolescent male and female participants in a community-based one-to-one mentoring program whose relationships ended early. Line-by-line coding and a narrative approach to a thematic analysis of the interview transcripts yielded six salient factors that contributed to the demise of these mentoring relationships: (a) mentor or protege abandonment, (b) perceived lack of protege motivation, (c) unfulfilled expectations, (d) deficiencies in mentor relational skills, including the inability to bridge cultural divides, (e) family interference, and (f) inadequate agency support. (Contains 1 table and 1 note.)