Power changes have been identified as a frequent and unintended consequence of the implementation of computerized physician order entry (CPOE). However, no previous study has described the degree or direction of power change, or even confirmed that such a relationship exists. Using a validated, standardized instrument for measuring personal power, we collected data from 276 healthcare workers in two different hospitals before and after implementation of CPOE. We identified a significant correlation between power perceptions and attitudes toward CPOE. Examining the direction of change by healthcare position, we found that the power perception values decreased for all positions and that attitudes toward CPOE varied based on use of the system. Understanding the relationship between power and CPOE is the first step in enabling systems developers to change the direction of power changes from negative to positive.