1. Given the high frequency of medication errors with resultant patient harm and cost, their prevention is a worldwide priority for health systems. 2. Systems that use information technology (IT), such as computerized physician order entry, automated dispensing, barcode medication administration, electronic medication reconciliation, and personal health records, are vital components of strategies to prevent medication errors, and a growing body of evidence calls for their widespread implementation. 3. However, important barriers, such as the high costs of such systems, must be addressed through economic incentives and government policies. 4. This paper provides a review of the current state of IT systems in preventing medication errors.