While most research on computerized provider order entry (CPOE) has focused on its role in preventing medication errors, CPOE—especially when combined with decision support—also has the potential to improve the quality and efficiency of care. This systematic review found that decision support systems (DSS) within CPOE increased adherence to radiology test ordering guidelines, resulting in an overall decrease in radiology utilization. These findings have the potential to improve patient safety as well, given the concern that unnecessary imaging studies may expose patients to dangerous levels of radiation. Prior studies have also shown that combining CPOE with DSS can improve diagnostic performance and encourage appropriate use of prophylactic medications.