BACKGROUND: Appropriateness in GI endoscopy is critical to face the rising amount of demands. Education of physicians has been advocated to reduce the level of inappropriateness. OBJECTIVE: Our purpose was to assess the effectiveness of an educational program in determining a reduction of inappropriate colonoscopies in an open access system. DESIGN: Prospective study. SETTING: A single endoscopy unit in Italy. PATIENTS: A total of 495 consecutive outpatients referred to our endoscopy unit by family physicians for diagnostic colonoscopy before the educational course and 522 after its completion, for a total of 1017 patients. MAIN OUTCOME MEASUREMENTS: Inappropriate colonoscopy reduction rates, cost savings, and reduction of waiting lists were evaluated. RESULTS: With regard to inappropriate colonoscopies, the post-course group rate of inappropriateness was significantly lower than that of the pre-course group (P < or = .001). The economic savings for 1 year was estimated to be euro19,000. The reduction of the waiting list was about 15% of the original value. CONCLUSIONS: Education has a high incidence in reducing inappropriate colonoscopies in an open-access system determining reduction of costs and waiting lists.