Computer technology has the potential to provide rich resources for language teaching and learning. However, it continues to be underutilized, even though its availability, familiarity, and sophistication are steadily increasing. This case study explored the way in which three language instructors' beliefs about language teaching and learning affected their use of computers in teaching in a postsecondary context. Data consisted of six weeks of observations of classrooms and computer labs and interviews with the three instructors. The findings suggest that the instructors' beliefs about interaction affected their use of computers significantly more than their technological expertise, and imply that for computers to be used more widely, teacher preparation needs to take into consideration instructors' beliefs and approaches to language teaching. (Contains 4 notes, 1 table and 1 figure.)