In Afghanistan, adolescents and young people are the most important at risk groups for substance abuse. Considering the importance of model-based interventions in this group, this study aims to design and validate a questionnaire based on the Health Belief Model (HBM) for assessing the beliefs of Afghan students regarding substance abuse prevention behavior. This study was conducted in two stages. In the first stage, the items of the questionnaire were designed by conducting a combined documentary literature review and qualitative study. In the next step, its psychometric properties were evaluated through qualitative and quantitative face and content validity (CVR & CVR) and structural validity (exploratory factor analysis). Finally, internal consisitency through Cronbach's alpha as well as reliability was assessed. To above steps, the SPSS version 18 was applied. 57 items were obtained for the questionnaire by performing a qualitative study and using existing scientific sources for literature review. In checking the face validity of the questionnaire items quantitatively (calculating the impact score), the impact score of all items was above 1.5. The CVR of each item was more than 0.8 and their CVI was more than 0.79. In EFA (using the information of 408 students with average age of 23 years old), the final model was confirmed with 38 related to the main HBM constructs in 5 factors, which covered about 40% of the variance. Acceptable values of Cronbach's alpha between 0.71 and 0.81 for all factors confirmed the reliability of the questionnaire. The HBM-SAPQA obtained the acceptable validity/reliability to apply the beliefs of Afghan students regarding substance abuse preventive behavior.