One major safety advantage of computerized provider order entry (CPOE) systems lies in their ability to prevent adverse drug events due to prescribing errors. In the outpatient setting, use of electronic prescriptions is growing thanks to studies demonstrating that e-prescribing reduces medication errors. However, as with CPOE in general, increasing use of e-prescribing is leading to greater recognition of new types of errors associated with this new technology. This study analyzed the frequency of unintended discrepancies in e-prescriptions from three primary care clinics by comparing the prescription information in the prescribing physician's note with the order entered into the e-prescribing system and the medication ultimately dispensed by the pharmacy. The investigators found that errors occurred at each stage of the process, with a small but significant rate of discrepancies between both physician notes and e-prescriptions and between e-prescriptions and the medication dispensed. These errors often occurred when providers entered free-text instructions into the e-prescribing system, as found in prior research. The potential safety benefits and hazards of e-prescribing are discussed in detail in an AHRQ WebM&M commentary.