To identify success factors for implementing computerized physician order entry (CPOE), our research team took both a top-down and bottom-up approach and reconciled the results to develop twelve overarching principles to guide implementation. A consensus panel of experts produced ten Considerations with nearly 150 sub-considerations, and a three year project using qualitative methods at multiple successful sites for a grounded theory approach yielded ten general themes with 24 sub-themes. After reconciliation using a meta-matrix approach, twelve Principles, which cluster into groups forming the mnemonic CPOE emerged. Computer technology principles include: temporal concerns; technology and meeting information needs; multidimensional integration; and costs. Personal principles are: value to users and tradeoffs; essential people; and training and support. Organizational principles include: foundational underpinnings; collaborative project management; terms, concepts and connotations; and improvement through evaluation and learning. Finally, Environmental issues include the motivation and context for implementing such systems.