The aim of this study was to determine the effects of teacher training programs on pre-service mathematics teachers' beliefs about mathematics. The sample of the study consisted of 173 pre-service mathematics teachers from an education faculty in the Central Anatolia Region of Turkey. The data were obtained from an open-ended questionnaire, categorized in terms of content analysis and analyzed quantitatively. The results of the study showed that there was no statistical difference between both elementary and secondary pre-service mathematics teachers' beliefs from when they started the teaching program to when they graduated from the programs. Yet, the mean scores about mathematical beliefs in the senior class were higher than those of the freshman class.