Introduction: Substance abuse among school age has become an issue of concern and public health problems throughout the world. Aim: To assess knowledge and attitudes of teachers about substance abuse. Subjects and method: A descriptive research design used in four secondary schools which selected by simple random sampling; (490) teachers included in the study. Two tools used; tool (1): self-administrative questionnaire included two parts; Part (1): Included questions regarding personal data. Part (2): teachers' knowledge about substances abuse included 17questions as definition, types, and risk factors. Tool (2): teachers' attitude about substance abuse Results: There was a statistically significant difference between teachers' attitude regarding substance abuse and their level of education. Conclusion: Less than half of study sample had poor knowledge about substance abuse while the majority of the teachers had positive attitude regarding dangerous of substance abuse. Recommendation: Health education for teachers about importance of closed monitoring and supervision for school age children for early detection of substances abuse.