The benefits of computerized physician order entry have been widely recognized, although few institutions have successfully installed these systems. Obstacles to successful implementation are organizational as well as technical. In the spring of 2000, following a 4-year period of planning and customization, a 9-month pilot project, and a 14-month hiatus for year 2000, the Ohio State University Health System extensively implemented physician order entry across inpatient units. Implementation for specialty and community services is targeted for completion in 2002. On implemented units, all orders are processed through the system, with 80 percent being entered by physicians and the rest by nursing or other licensed care providers. The system is deployable across diverse clinical environments, focused on physicians as the primary users, and accepted by clinicians. These are the three criteria by which the authors measured the success of their implementation. They believe that the availability of specialty-specific order sets, the engagement of physician leadership, and a large-scale system implementation were key strategic factors that enabled physician-users to accept a physician order entry system despite significant changes in workflow.