Computerized provider order entry (CPOE) is a widely recommended intervention to prevent medication errors, but thus far, the effect of its implementation on medication error rates has been inconsistent. This meta-analysis of 10 published studies found a 48% reduction in the likelihood of a prescribing error when using CPOE compared with paper-based orders, which translates into more than 17 million medication errors prevented yearly. However, the study did not formally assess the effect of CPOE on clinical adverse drug events. Also, as prior research has pointed out, variations in medication error definitions between studies makes it difficult to determine the true prevalence of medication errors in different clinical settings. Nonetheless, as CPOE usage continues to grow widely, this study adds support for its use as a patient safety strategy.