Objective: To investigate the risk of self-injury in parentally cancer-bereaved youth compared with their nonbereaved peers. Design: Population-based study of cancer-bereaved youth and a random sample of matched population controls. Setting: Sweden in 2009 and 2010. Participants: A total of 952 youth (74.8%) confirmed to be eligible for the study returned the questionnaire: 622 (73.1%) of 851 eligible young adults who lost a parent to cancer between the ages of 13 and 16 years, in 2000 to 2003, and 330 (78.4%) of 451 nonbereaved peers. Main Exposure: Cancer bereavement or nonbreavement during the teenage years. Main Outcome Measures: Unadjusted and adjusted odds ratios (ORs) of self-injury after January 1, 2000. Results: Among cancer-bereaved youth, 120 (19.5%) reported self-injury compared with 35 (10.6%) of their nonbereaved peers, yielding an OR of 2.0 (95% CI, 1.4-3.0). After controlling for potential confounding factors in childhood (eg, having engaged in self-destructive behavior, having been bullied, having been sexually or physically abused, having no one to share joys and sorrows with, and sex), the adjusted OR was 2.3 (95% CI, 1.4-3.7). The OR for suicide attempts was 1.6 (95% CI, 0.8-3.0). Conclusions: One-fifth of cancer-bereaved youth reported self-injury, representing twice the odds for selfinjury in their nonbereaved peers, regardless of any of the adjustments we made. Raised awareness on a broad basis in health care and allied disciplines would enable identification and support provision to this vulnerable group.