OBJECTIVES: To assess the influence of a quality improvement initiative on the rate of potentially inappropriate medications (PIMs) in primary care elderly patients. METHODS: A 3-year, multi-phase prospective demonstration project targeting all 303 general practitioners (GPs) in the Local Health Authority (LHU) of Parma, Italy, was established in 2007. A panel of Parma LHU experts developed a list of PIMs deemed to be always avoided for older patients according to the literature. The quality improvement intervention delivered to GPs hinged upon increasing physicians’ awareness of prescribing for the elderly and included three key elements: i) the initial dissemination of the developed PIMs list, along with a list of alternative drugs to PIMs; ii) annual reviews of PIMs prevalence data; and (iii) a series of educational sessions on PIMs via academic detailing and case studies reviews. We used a pre-post design to analyze the change in quarterly rates of PIMs in elderly patients aged ³65 years in Parma LHU between the study start (pre-intervention - 2007 fourth quarter (Q4)) and the end of the study (post-intervention – 2009 Q4), using a neighboring LHU similar in size as a comparator. RESULTS: The prescription rate of PIMs in the elderly of Parma LHU declined by 19%, from 6.3% pre-intervention (2007 Q4) to 5.1% post-intervention (2009 Q4), compared to a 12% reduction in the same time period in the comparator LHU, from 6.8% to 5.9%.  The degree of decline in the rate of PIMs was significantly greater in the LHU of Parma (Breslow-Day test, p=0.004).  CONCLUSIONS: A quality intervention program looking at improving knowledge in primary care physicians on prescribing for the elderly patients resulted in a substantial reduction of the rate of PIMs.  Additional approaches targeting specific medications or physician characteristics should be developed to further reduce PIMs rates.