Objective: The purpose of this study was to determine the effect of educational packages on knowledge of substance addiction and complication among different levels of students in Tehran city.

Materials & Methods: An interventional study was designed in that three group of different levels of students using pre-test and post-test questionnaires, before the study of educational packages and after the study of educational packages.

Results: The mean total scores of students before and after the study of educational packages were respectively 7.61 and 9.44 that has been demonstrated knowledge of different levels of students before and after intervention in students of primary (except fourth and fifth class), middle and high school was significantly increases.In other words with confidence of %95 can be said training about substance addiction and complication in increase of knowledge of different educational levels have been effective.

Conclusion: According to the results of this study the key role of educational program to reveal itself in demand reduction strategies and primary prevention.