ABSTRACT
Educational program for drug abuse prevention should emphasize on trans-theoretical model [TTM]. This study was designed to survey effects of TTM in substance abuse prevention among petrochemical workers in Iran. This randomized clinical trial was done on 181 workers of petrochemical company in Assaluyeh. Education program was prepared according to resistance skills, decisional balance, processes of change [cognitive and behavior], self esteem, self-efficacy and life skills. Intervention group received educational program by lecture and group discussion about principles of TTM. Intervention and control groups was compared before and 5 month after intervention. Intervention group received educational package, including posters and pamphlets, within 5 months. Educational activities had significant impact on awareness of substance abuse, risk factors and protective factors, self efficacy, decisional balance for apply resistance skills contain pros and cons, attitude and also processes of change on resistance skills in cognitive and behavioral domain, while there found no significant changes in control group. According to positive effects of TTM as a educational program for drug abuse prevention, application of this model recommended in prevention of drug abuse among industrial workers