The aim of this research is to look into the roles of families' social situation and cohesion in adolescent auto-aggressiveness in Croatia. The research was conducted on a sample of Zagreb high school students which encompassed 701 pupils of both genders aged 14-19. The basic demographic data were obtained using the Structured Demographic and Family Data Questionnaire. Auto-aggressiveness was tested using a section of the Report on Youth Aged 11-18 and the Scale of Auto-destructiveness--SAD, whereas the family cohesion was tested with the Family Adaptability and Cohesion Evaluation Scales FACES III. The obtained results show differences according to the gender: girls are more prone to auto-aggressiveness than boys (t = -3.385, df = 565, p = 0.001) and girls more often show symptoms of destructiveness (t = -3.809, df = 637, p < 0.001) and anxiety (t = -6.562, df = 640, p < 0.001), while boys show pronounced aggressiveness (t = 2.655, df = 653, p = 0.008). Significant family factors associated with auto-aggressiveness are parents' marital status (chi2 = 18.039, df = 4, p = 0.001), their financial situation (F(2.548) = 4.604, p = 0.010), alcoholic father (chi2 = 9.270, df = 2, p = 0.010), mentally ill mother (t = 5.264, df = 541, p < 0.001), as well as mentally ill father (t = 4.744, df = 529, p < 0.001), and corporal punishment by mother (F(2.542) = 8.132, p < 0.001) or father (F(2.530) = 5.341, p = 0.005). Adolescents from split families show more auto-aggressiveness. Family cohesion appears to be considerably associated with auto-aggressiveness and the adolescents that see their families as less cohesive have more mental problems (chi2 = 29.98, df = 2, p < 0.001). There is a connection between auto-destructive behavior in adolescents and family factors. Knowledge of family's social situation and cohesion may help understand, prevent and treat auto-aggressiveness in adolescents.