Introduction & Objective: Driving under the influence of drugs is considered a social pathology that has adverse effects on a society. This study aimed to investigate the effect of substance abuse educational program among the bus drivers on the basis of the theory of planned be-havior. Materials & Methods: This quasi-experimental study was conducted on 80 suburban bus drivers working at Hamadan transportation terminal. The bus drivers were randomly divided in two equal groups (intervention and control). Intervention program design was implemented after diagnostic evaluation. The effect of educational intervention on behavior was assessed two months after the last training session. SPSS -16 was employed for data analysis.

 Results: After the educational intervention, the average rates of the constructs of the theory of planned behavior in the intervention group significantly increased but these changes were not significant in the control group: attitude (t=9.53, P=0.000), subjective Norms (t=9.59, P=0.000), perceived behavioral control (t=-4.14, P =0.000). Also, behavioral intention to substance abuse avoidance and current behavior for substance abuse significantly decreased in the intervention group as compared to the control group (P<0.05). Behavioral intention and current behavior in the intervention group subsided from 15 and 12 people before the educational intervention to 3 and 0 people at the end of the educational program, respec-tively.

Conclusion: The results showed that using the theory of planned behavior along with the train-ing skills strategies to resist drug abuse has a significant impact to create a psychiatric immu-nization and substance refusal in drivers.