Objective: The authors' purpose in this research was to establish estimates of the prevalence and correlates of nonsuicidal self-injury among university students. Participants: The authors recruited participants (N = 2, 843) from a random sample of 5, 021 undergraduate and graduate students attending a large midwestern public university. Methods: Using an Internet-based survey, the authors measured the prevalence of self-injury and potential risk factors, including depression, anxiety, eating disorders, suicidal thoughts, and negative health behaviors. Results: Seven percent of students reported any self-injury over the previous 4 weeks. Factors associated with a significantly higher likelihood (p less than 0.05) of self-injury included cigarette smoking, concurrent depressive and anxiety disorders, and for men, growing up in a family of low socioeconomic status and having symptoms of eating disorders. Only 26% of those who reported self-injury received mental health therapy or medication in the previous year. Conclusions: Students who harm themselves experience high anxiety and distress, yet are unlikely to seek help. (Contains 2 tables and 1 figure.)