One of the aspects that should be prepared to attain high-performing athletes is the mental factor. Mental toughness must be identified during athlete practice preparation to help to keep athletes appropriate while they encounter difficulty in a match or under pressure during the competition, and use intervention measures so that they do not become stressed quickly. The study aimed to develop a tool to detect the mental toughness of athletes and validate its psychometric properties. The participants included 218 athletes from Bekasi, Indonesia. The data were collected via online form randomly. Rasch analysis was utilized to evaluate the validity and reliability of the mental toughness questionnaire in the Indonesian version. Item fit criteria were assessed based on Rasch parameters. The rating scale function was performed to check how well the participants comprehend the rating scale categories in the Mental Toughness Questionnaire. The results show that the mental toughness questionnaire in the Indonesian version achieves the validity and reliability criteria based on Rasch parameters. All items fit based on threshold item fit in the Rasch parameter, and we confirm that three rating scales are better than four rating scales.