In recent years, much attention has been given to the need for more empirical research to evaluate training programs that help prepare graduate students for their current and future teaching responsibilities. The present study investigated the effectiveness of a training workshop for graduate students who had varying levels of experience and diverse cultural backgrounds. Results indicated that over the course of training participants significantly increased their self-efficacy and effective teaching behaviours and decreased their public speaking apprehension. Although participants with varying levels of experience as well as participants with Canadian and international backgrounds benefited from the program, the results highlighted the need for additional teaching development opportunities for international graduate students. (Contains 1 table.)