Health sciences librarians at the University of Washington (UW) are partners in the evolution of Internet-based clinical information systems for two medical centers, University of Washington Medical Center and Harborview Medical Center, as well as the UW Primary Care Network clinics. Librarians lead information resource and systems development projects and play a variety of roles including facilitator, publisher, integrator, and educator. These efforts have been coordinated with parallel development efforts by the Integrated Advanced Information Management Systems (IAIMS) clinical informatics group in developing electronic medical record systems and clinical decision support tools. The outcome is MINDscape, a very heavily used Web view of the patient medical record with tightly integrated knowledge resources as well as numerous Web-accessible information resources and tools. The goal of this article is to provide a case study of librarian involvement in institutional information systems development at UW and to illustrate the variety of roles that librarians can assume in hospital settings.