Objective: Gaming motivations are a central aspect of playing video games, and their importance to understanding both healthy and problematic gaming behavior has been increasingly elucidated. In this study, we aimed to translate the 18-item Gaming Motivation Scale (GAMS-18) to Persian and validate it in a population of Persian speaking gamers, specifically for the assessment of online gaming. Methods: After translation from English to Persian, content validity of the questionnaire was assessed by a panel of experts and test–retest reliability was calculated in a sample of 70 students. Data from an online survey of 791 Iranian online gamers were used for the assessment of construct validity using confirmatory factor analysis. Results: The item content validity index and the scale content validity index for clarity and relevance ranged from 0.80 to 1.00. Internal consistency reliability of the GAMS-18 was 0.90 and the test–retest reliability was 0.89. The test–retest reliability of the GAMS-18 was 0.89, and the internal consistency was 0.90. The GAMS factors had acceptable correlation with other motivational scale such as Player Experience of Need Satisfaction. Incorporating the proposed additional error paths improved the model fit to an acceptable level. Conclusion The Persian version of the GAMS can assess digital gaming behavior based on the six self-determination theory motivation types, and measures different aspects of motivation that other instruments. It is also demonstrated to have good reliability and validity and could be used in research on the motivations of online gamers in Persian-speaking populations.