Computerized physician order entry (CPOE) has been shown to reduce preventable, potential adverse events. Despite this evidence, fewer than 5 percent of U.S. hospitals have fully implemented these systems. We assess empirically alternative reasons for low CPOE implementation using data from various sources. We find that CPOE is related to hospital ownership and teaching status; government and teaching hospitals are much more likely than other hospital types are to invest in CPOE. Hospital profitability is not associated with CPOE investment. Although greater diffusion of CPOE is needed, it might have to await continuing publicity efforts and substantial reimbursement system changes.