Little is known about the extent to which minor self-harm in the general population is associated with psychiatric disorder. A population-based sample of 980 young adults was interviewed independently about past-year suicidal and self-harm behavior and thoughts, and psychiatric disorders. Self-harm included self-harmful behaviors such as self-battery, as well as traditional methods of suicide (ICD [International Classification of Diseases] self-harm). All with ICD self-harm and most with other self-harmful behavior met the criteria for DSM-IV disorder. Suicidal/self-harmful thoughts increased the odds for self-harm, even in men without psychiatric disorder (odds ratio 4.9, 95% confidence interval 1.3-17.9). Young adults engaging in even minor self-harm warrant screening for psychiatric disorder.