Background: Recent research on academic-industrial research relationships in the life sciences has examined their frequency, benefits, risks, and evolution from the standpoint of industrial sponsors of research. We collected information on the extent and effects of academic-industrial research relationships from the standpoint of faculty members who participate in them. Methods: We used a mailed questionnaire to collect data between October 1994 and April 1995 from 2052 faculty members (of 3169 eligible respondents; response rate, 65 percent) in the life sciences at the 50 U.S. universities receiving the most research funding from the National Institutes of Health. Results: Twenty-eight percent of the respondents received research support from industry. Faculty members receiving industrial funds had more peer-reviewed articles published in the previous three years, participated in more administrative activities in their institutions or disciplines, and were more commercially active than faculty members without such funding. However, faculty members receiving more than two thirds of their research support from industry were less academically productive than those receiving a lower level of industrial support, and their articles were less influential than those by researchers with no industrial support. Faculty members with industrial support were significantly more likely than those without industrial support to report that trade secrets had resulted from their work (14.5 percent vs. 4.7 percent, P<0.001) and that they had taken commercial considerations into account when choosing research topics (35 percent vs. 14 percent, P<0.001). Conclusions: Faculty members with industrial research support are at least as productive academically as those without such support and are more productive commercially. However, faculty members who have research relationships with industry are more likely to restrict their communication with colleagues, and high levels of industrial support may be associated with less academic activity without evidence of proportional increases in commercial productivity.