The purpose of the present study was to investigate the rate of deliberate self-harm in 15-year-old Swedish adolescents, gender differences in this behavior, and possible associations with self-esteem and mindfulness. For this purpose, we developed a simplified version of Gratz's (2001) Deliberate Self-Harm Inventory (DSHI), and carried out a pilot study with 123 adolescents from three different schools in southern Sweden. The results showed that 65.9% of the adolescents reported having engaged in some kind of deliberate self-harm at least once; 41.5% reported at least one kind of self-harm more than once; and 13.8% reported at least one kind of deliberate self-harm behavior "many times". Although there were no overall gender differences in self-harm, the girls reported significantly more of cutting wrists, arms and other body areas than the boys. High rates of deliberate self-harm were associated with low self-esteem and low mindfulness.