Background This study examined the prevalence of non-suicidal self-injury (NSSI), suicide attempts, suicide threats and suicidal ideation in a German school sample and compared the rates with a similar sample of adolescents from the midwestern USA by using cross-nationally validated assessment tools. Method Data were provided from 665 adolescents (mean age 14.8 years, s.d.=0.66, range 14-17 years) in a school setting. Students completed the Self-Harm Behavior Questionnaire (SHBQ), the Ottawa Self-Injury Inventory (OSI) and a German version of the Center for Epidemiological Studies-Depression Scale (CES-D). Results A quarter of the participants (25.6%) endorsed at least one act of NSSI in their life, and 9.5% of those students answered that they had hurt themselves repetitively (more than four times). Forty-three (6.5%) of the students reported a history of a suicide attempt. No statistically significant differences were observed between the German and US samples in terms of self-injury or suicidal behaviors. Conclusions By using the same validated assessment tools, no differences were found in the prevalence and characteristics of self-injury and suicidal behaviors between adolescents from Germany and the USA. Thus, it seems that NSSI has to be understood as worldwide phenomenon, at least in Western cultures