This research aimed to reveal the relationship between self-harm behaviour, body image, and self-esteem, and examined whether there was a difference between the body image and self-esteem of the adolescents who exhibited self-harm behaviour and those who did not. The study was conducted with the participation of 263 high school students — 143 females (54.3%) and 120 males (45.6%) — who studied in various high schools in the Trabzon province, Turkey. The students’ ages ranged from 15 to 18; the mean age was 17.02 (SD = 1.59). The research was conducted using the Inventory of Statements about Self-Injury, the Body Perception Scale, the Rosenberg Self-Esteem Scale, and a personal information form. The research concluded that there was a significant relationship between body image and self-esteem of the adolescents, and that body image and self-esteem were the significant regressors of self-harm behaviour.