Nonsuicidal self-injury (NSSI) is a significant issue among college students but few resources are available to college mental health professionals. This article consolidates extant knowledge on NSSI from the empirical and clinical literature, including common NSSI characteristics (rates, methods, demographics, and concomitants), intrapersonal and social functions, and NSSI's relation to suicide. Practical strategies for assessing NSSI among students are presented, as are empirically informed treatments. With this knowledge, college mental health professionals will have a theoretical and practical understanding of NSSI and will be better equipped to work with students who self-injure.