Bangladesh initiated inclusive education in state schools in 2010 and introduced reforms to the teacher education program in 2015 for its effective implementation. However, studies have found that the current teacher training is insufficient for government primary school teachers in Bangladesh. It is important to understand their needs to design more effective teacher training programs. This study developed a questionnaire to reveal Bangladeshi government primary school teachers’ training needs for inclusive education. Development of the questionnaire was conducted in three stages: For Phase 1, the domains of the teachers’ needs were identified; in Phase 2, domain items were developed and tested; and in Phase 3, the psychometric properties of the tool were examined for reliability and validity. This research mainly focuses on the results of the reliability and validity testing of the questionnaire. The questionnaire originally comprised 48 items within nine subscales. Eventually, 37 items were selected within eight subscales after validity and reliability testing demonstrated good reliability, internal consistency, and convergent validity. All but one of the subscales are distinct and unidimensional.