This article evaluates how physicians draw upon scientific and other forms of knowledge in different professional communities. We argue that because physicians will draw upon clinical research findings to improve their reputation with colleagues, and because the terms for accruing esteem in an academic hospital may differ depending on the dominant task structure of the organization, the form of knowledge that is valued by a physician will vary with his or her hospital's level of prestige. We use social network and multivariate analyses to test this theory in six U.S. hospitals with varying levels of prestige. We find that in lower-prestige hospitals, physicians can improve their reputation by reading a relatively broad range of scientific journals, whereas in higher-prestige hospitals, esteem is allocated to those with a more elite medical school pedigree. Statistically significant differences also exist between hospitals in terms of whether work with patients is valued, with physicians who engage in more clinical activity in the highest-ranked hospitals receiving less esteem from their colleagues. We finish by discussing how the functioning of higher- and lower-prestige hospitals is interconnected in ways that sustain both the development of innovations and their widespread adoption. (Contains 3 tables, 1 figure and 7 notes.)