AbstractNon‐suicidal self‐injury (NSSI) is a growing clinical problem, especially among adolescents and young adults. Anecdotal accounts, clinical reports, and popular media sources suggest that observing the blood resulting from NSSI often plays an important role in the behavior's reinforcement. However, research to date has not systematically assessed the role of blood in NSSI. The current study examined this phenomenon in 64 young adults from a college population with histories of non‐suicidal skin‐cutting. Approximately half the participants reported it was important to see blood during NSSI. These individuals reported spending five minutes or less looking at the blood after each instance of NSSI, and that seeing blood served several functions including “to relieve tension” and “makes me feel calm.” In addition, wanting to see blood was associated with greater lifetime frequency of skin‐cutting and greater endorsement of intrapersonal functions for NSSI (e.g., affect regulation, self‐punishment). Finally, participants who reported wanting to see blood were more likely to endorse symptoms of bulimia nervosa and borderline personality disorder. Theoretical and clinical implications are discussed. © 2010 Wiley Periodicals, Inc. J Clin Psychol 66: 1–8, 2010.