In the past decade, there has been limited longitudinal qualitative research examining the effects of training programs on graduate students’ teaching performance. One gap in this research is a discussion of Teaching Assistants (TAs) who resist such programs and an examination of strategies for overcoming this resistance. This action research study attempts to fill that gap by evaluating the relationship between TAs’ participation in one university’s Certificate in University Teaching (CUT) program and their resistance to its pedagogical strategies. The study defines the types of resistance and analyzes the reasons behind it. Findings address ways to more effectively reach resisting TAs and improve our own teaching practices.