Substantial research has been done on inpatient provider order entry systems with varying degrees of clinical decision support. Such studies have examined how these technologies impact patient safety as well as the quality and cost of care. However, given that most medical care and prescriptions are administered in an ambulatory setting, the dearth of research on ACPOE systems is quite astonishing. This knowledge gap demonstrates the need for an integrative and systematic literature review that attempts to assess the research done on computerized patient safety interventions in ambulatory care. This review’s findings provided adequate evidence that ACPOE systems are effective interventions for reducing medication errors. Other evidence further indicated that, in terms of functional capabilities, commercial ACPOE and e-prescribing systems may be catching up with their homegrown counterparts. PDA-based CDSSs were depicted as useful tools for raising adherence to guidelines and inducing safer prescribing. These findings suggest that ACPOE And PDA-based CDS systems show promise for improving safety and healthcare quality in ambulatory settings. ACPOE specifically, tended to have more advanced CDS attributes but, nonetheless, showed more negative results compared to the e-prescribing systems. Close scrutiny should therefore be given to the elements of decision support that ambulatory physicians find most useful.