Graduate students play a major role in teaching in higher education, particularly in undergraduate programs. The purpose of the present study was two-fold: first, to identify graduate students' motives for working as graduate teaching assistants (GTAs), describe some aspects of their work, and ascertain their perceived benefits; second, to predict GTAs' benefits as a function of their individual background characteristics, motives, job difficulties, and richness of professional interactions with the course instructor. Data were collected from 189 GTAs who led discussion groups at a large research university in Israel by means of an internet questionnaire. Findings revealed that graduate students accepted the position of GTA mainly for extrinsic reasons, such as salary and convenience. They claimed to have faced few difficulties and that their professional interactions with the course instructors focused more on job responsibilities and less on pedagogical issues. They reported having gained a greater understanding of course content and improved teaching skills due to their experience as GTAs. Richness of contact with the course instructor, motives, difficulties, and faculty match significantly contributed to predicting perceived benefits. The implications of the results are discussed.