This article examines the relationship between the supervision of graduate students and university faculty research performance. We find that the supervision of Ph.D. students who have projects related to their supervisor's research has an independent effect on faculty members' scientific productivity in the natural and medical sciences and technology, but not in the humanities and social sciences. The relationship between the supervision of project related major subject students and the faculty members' productivity is only significant in the social sciences. These results are generally supported by data on faculty attitudes toward the supervision of graduate students. Those who supervised Ph.D. students gave a considerably more favourable assessment of the importance of supervision for their own research than those who only supervised major subject students, and the proportion of faculty members who answered that supervision of Ph.D. students was part of their own research to a great extent, was very much higher in the natural and medical sciences and technology than in the humanities and social sciences.