OBJECTIVES Although clinical-practice-guidelines (CPGs) are implemented to improve the quality, efficiency, and consistency of health care, CPGs generally have limited effect in changing physician behavior. The objective of this study was to design, implement and evaluate an intervention for CPG implementation tailored to fit the organizational culture of an Israeli HMO. The test-case for this intervention was implementation of CPGs for empiric antibiotic treatment of uncomplicated cystitis in adult women. METHODS . Personalized feedback containing data on individual prescribing patterns sent by specialists in family practice and infectious diseases, and an academic lecture at a HMO sponsored conference were designed. These two educational interventions were implemented both separately and combined amongst HMO primary care physicians. Steps were taken to ensure that the interventions were carried out with an eye to preserving the atmosphere of mutual professional respect between HMO management and the physicians. The objective of the interventions was to improve rate of prescribing of the first line drug nitrofurantoin or adherence to the three day recommended duration of treatment with ofloxacin if prescribed. Pre and Post intervention prescribing patterns in the three intervention groups and the control group were calculated. RESULTS The lecture alone improved rate of adherence to the guidelines by ~7% (95% CI=1.3, 13.6), but a short duration of effect was observed. Feedback alone was sufficient to improve the rate of adherence to the guidelines by 19.4% (95% CI =16.7, 22.1) and was not observed to be inferior to the combined intervention strategy. No significant change in prescribing patterns was observed amongst physicians in the control group. CONCLUSIONS This model may be useful for promoting other evidence-based messages via a mechanism for presenting individual data to physicians while being sensitive to professional respect.