This study investigated, characteristics of the non-suicidal self-injury (NSSI) behaviors and behaviors' relationship with the sociodemographic characteristics, psychological problems and other features like daily life activities, between the ages of 12 and 17 years in the central district Izmit of Kocaeli; 555 students whose data included to study received a sociodemographic questionnaire (SQ) and Youth Self-Report (YSR). Students, who reported that they had NSSI, were additionally evaluated with the Inventory of Statements About Self-injury (ISAS). We found out a significant correlation between NSSI and the psychological problems, habits with addiction-forming potential, some daily life activities and making friends with negative characteristics. We concluded that prevention of the risk factors related to NSSI might be effective to avoid the development of this behavior. And diagnosing the behavior in the onset, might provide more effective and long-lasting results and enable the adolescent to get over this risky period with minimal harm.