Computerized physician order entry (CPOE) has been shown to improve quality, and to reduce resource utilization, but most available data suggest that it takes longer to enter orders using CPOE. We had previously implemented a CPOE system, and elected to evaluate its impact on physician time in the new setting. To do this, we performed a prospective study using random reminder methodology. Key findings were that interns spent 9.0% of their time ordering with CPOE, compared to 2.1% before, although CPOE saved them an additional 2% of time, so that the net difference was 5% of their total time. However, this is counterbalanced by decreased time for other personnel such as nursing and pharmacy, and by the quality and efficiency changes. We conclude that while CPOE has many benefits, it represents a major process change, and organizations must factor this in when they implement it.