Despite the benefits of computerized provider order entry (CPOE), numerous reports of unexpected CPOE-related safety concerns have surfaced. As part of a larger project to improve the safety of electronic health records (EHRs), we developed and field tested a CPOE "safety self-assessment" guide through literature searches, expert opinion, and site visits. We then conducted a field test of this guide with nine hospital chief medical informatics officers (CMIOs), who were identified through the Association of Medical Directors of Information Systems. The CPOE safety self-assessment guide was sent electronically to the CMIOs. Once the assessments were returned, we conducted structured telephone interviews for further comments about the guide's format and content. The CMIOs in our study found the CPOE safety guide useful and relatively easy to complete, taking no more than 30 minutes. Analysis of responses to the guide suggest that most recommended practices were implemented inconsistently across facilities. Despite consensus for certain CPOE best practices in the medical literature and among experts, there appeared to be considerable variation among CMIOs' opinions of best practices. Interview data suggested this inconsistency was mostly due to system limitations and/or differing opinions about the necessity of certain EHR-related safety measures. Despite the absence of consensus on best practices, a self-assessment safety guide provides a practical starting point for organizations to assess and improve safety and the effectiveness of their CPOE system.