A few studies on adult clinical samples have demonstrated that dissociation predicts self-harm behavior without intent to die. Furthermore, a similar association has been found from selected adolescent populations. However, no studies have been published on the association between dissociation and self-harm behavior in general populations of either adults or adolescents. We investigated whether a high level of dissociation predicts self-cutting or other self-harm behavior in a Finnish general population sample of 4019 adolescents aged between 13 and 18 years. Those with a high level of dissociation measured with the Adolescent Dissociative Experiences Scale had a higher risk of current self-cutting and other self-harm behavior, even when adjusted for several possible confounding factors. Self-cutting adolescents had higher Adolescent Dissociative Experiences Scale scores than those displaying other kinds of self-harm behavior. These results indicate that a high level of dissociation is an independent risk factor for self-harm behavior in adolescents, and may have value both in clinical work and further research.