Librarians have often questioned the usefulness of the proceedings of biomedical meetings. Because articles in proceedings are similar to journal articles, the usefulness of the two were compared. Thirty-two monographic cardiovascular proceedings were compared to thirty-five cardiovascular journals, all published in 1978. Citations to the articles in these samples were counted for the years 1978, 1979, and 1980, and an impact factor was calculated for each proceedings and journal. The mean impact factor of the journals (3.86) was significantly higher than the mean impact factor of the proceedings (0.98, p less than .001). A short delay in publication of a proceedings was not associated with a higher impact factor. There were no differences in impact factors between U.S. and non-U.S. meeting sites. Proceedings of "hot" topics were not associated with higher impact factors, and multiple-index coverage of proceedings was only weakly associated (tau = 0.27) with higher impact factors. While camera-ready proceedings had a significantly higher mean impact factor (2.37) than typeset proceedings (0.66, p less than .02), selection based on printing method is not recommended. It is concluded that most libraries can safely forego the purchase of monographic proceedings. If a library needs monographic proceedings, it should purchase only those recommended by subject specialists.