The purpose of this study is to evaluate the effectiveness of Global Citizenship Training Program (GCTP) prepared for teacher candidates. The training program lasted for 13 sessions and 32 volunteering Turkish teacher candidates participated in the program. The mixed method was utilized for this study. The pre-test and post-test scores of teacher candidates from "Global Citizenship Competency Perception Scale" (GCCPS) and "The Respect of Differences Scale" (RDS) make up the quantitative part of the study, while participant diaries and evaluation forms consisting open-ended items make up the qualitative part of the study. The results of the study reveal that GCTP has positive effects on teacher candidates' global citizenship competency perception and level of respect for differences. The diaries also show that the training enabled teacher candidates: to deepen their knowledge of global citizenship, to make a detailed analysis and inquire various issues like multiculturalism, women, children and handicapped individuals' rights, to develop their global citizenship competencies, to face their own bias and change their perspectives. Also, they expressed that the activities and materials used in the training were effective. Film activities, script writing and creative drama are identified as the most enjoyed activities by teacher candidates.