The authors developed and implemented a toolkit of 11 best practices for patient safety in a health system's ambulatory care clinics. The best practices (which overlapped significantly with the Joint Commission on Accreditation of Healthcare Organizations National Patient Safety Goals) focused on medication safety, including such items as maintaining an accurate medication and allergy list, standardizing prescription writing, educating about look-alike and sound-alike drugs, and removing IV potassium chloride from all locations. Best practices that required system-wide changes (ie, assessing medication list accuracy) required considerable organizational commitment. The practices significantly improved the accuracy of patient medication and allergy lists during the study.