Background: Substance abuse among school students  may lead to criminal penalty in addition to possible physical, social, and psychological harm. Psychosocial support in schools focus on children's social and academic skills, including enhancing peer relationships, self-control, coping skills, social behaviors, and drug offer refusal skills.  Aim: to assess knowledge, self concept and attitude among school students toward protection against substance abuse . Study design: Descriptive design was utilized to conduct this study. Setting: this study was conducted at two schools (one school for male and one school for female). These are The New Heliopolis Preparatory School for Girls and El-Tabri Preparatory School for Boys at Cairo city. Subject: convenient sample of 262 students were recruited for conducting this study. Data collection tools: 1) Socio-demographic questionnaire for students. 2) knowledge and attitude about substance abuse. 3) Self Concept Scale..Results: the present study revealed that there was a highly statistically significant improvement regarding knowledge and attitude oscores post implementation of psycho social intervention program. In addition, there were highly statistically significant positive correlations between knowledge and attitude of studied students. Conclusion: there is a statistically significant relationship among students  knowledge, self concept and attitude concerning substance abuse. Recommendations:. Future programs should include the parents of adolescents to teach them  how to deal with their adolescents and to avoid risky behavior  that may occur at this age. Morover, hotlines must be available to solve immediate problems of adolescents.