Abstract: Introduction – Previous research suggests that Canadian academic health sciences librarians value knowledge of the health sciences and spend a considerable amount of time gaining and maintaining it. The current study replicates the earlier Canadian survey but employs a larger American sample to address three questions: Do academic health sciences librarians working in the United States find knowledge of the health sciences to be important, and if so, how do they acquire it? Do the attitudes of Canadian and American academic health sciences librarians differ with respect to subject knowledge? Methods – An invitation to participate in a Web-based survey was sent to 711 academic health sciences librarians working in the US; 154 participated. Results – Academic health sciences librarians in the US felt that keeping up with the scientific and medical literature was important to doing their jobs, although only 50% of respondents felt that a degree in the health sciences was somewhat or very useful. Discussion – Participating in professional organizations, visiting Web sites, and reading or browsing journals or magazines were rated by respondents as the best ways to become informed about the health sciences. Findings were similar to those of an earlier survey of Canadian academic health sciences librarians.