Previous studies revealed a high prevalence of nonsuicidal self-injury (NSSI) in western adolescents and suggested the existence of multiple self-injurer subgroups. This study examined the prevalence of NSSI among Hong Kong Chinese adolescents and compared different subgroups of self-injurers on several psychological correlates of NSSI related to borderline personality disorder. A total of 6,374 secondary school students (67.6% girls) completed self-report questionnaires. Multivariate analyses of variance and follow-up logistic regression analyses were used to compare differences between subgroups of self-injurers. Overall, 15% of adolescents reported engaging in NSSI. Gender differences varied regarding different self-injury methods. Repetitive self-injurers had more emotional and impulse-control problems than episodic ones. Severe NSSI adolescents were also more impulsive than mild NSSI adolescents. The frequency and severity of NSSI acted as two important dimensions in distinguishing between self-injurers. Clinical implications of these results are discussed.[Copyright of Routledge. Full article may be available at the publisher's website: http://dx.doi.org/10.1080/13811118.2011.540211]