Background: Exposure to abuse or neglect during childhood may associated with an increased risk of psychological, social, and behavioral impairment. Aim of study: to investigate the impact of childhood maltreatment on self-esteem and social competence among adolescence. Subjects and Methods: The study was conducted in two randomly selected secondary schools at Zagazig city using an analytic cross-sectional research design on 187 male and female students. Data were collected using a self-administered questionnaire with a maltreatment questionnaire, Rosenberg self-esteem scale, and the adolescent social self-efficacy scale. Results: Adolescents’ age range from 16 to 19 years, with almost equal gender distribution. In total, 39.0% of adolescents had no exposure to maltreatment, while 11.2% had high exposure; 71.7% had normal level of self-esteem, and 58.8% had moderate social self-efficacy. Maltreatment scores had positive correlations with adolescent’s age, number of male siblings, family size, and crowding index, and a negative correlation with family income. In multivariate analysis, maltreatment scores were negative predictors of self-esteem and social self-efficacy scores. Conclusion: Exposure to maltreatment is a significant negative predictor of self-esteem and social self-efficacy among adolescents. Recommendations The study recommends more active school nurses’ role in training adolescents, teachers, and counseling parents to improve their parenting strategies. Outreach programs to increase awareness about child maltreatment and their negative sequels on child development. School curricula should include educational sessions in life skills. Further research is proposed to examine the long-term effects of childhood maltreatment.