OBJECTIVE—To evaluate whether an electronic reminder integrated into a routine computer system increases the use of antiplatelet drugs for diabetic patients among Italian general practitioners (GPs). RESEARCH DESIGN AND METHODS—A randomized controlled trial was carried out among 300 GPs and their patients selected from the Health Search Database. Among these, 150 GPs (intervention group) received instructions to activate an electronic reminder plus a letter summarizing the beneficial effects of antiplatelet drugs in diabetic patients with at least one additional cardiovascular risk factor (“high risk”), whereas the other 150 GPs (control group) received only the letter. The electronic reminder, integrated into a standard software system for the management of the daily clinical practice, was displayed when every participating GP opened the medical record of diabetic patients aged ≥30 years. Only high-risk diabetic patients were included in the analysis. Patients were considered under antiplatelet treatment if they received two or more prescriptions at baseline and during the follow-up. RESULTS—We selected 15,343 high-risk diabetic patients, 7,313 belonging to GPs of the control group and 8,030 belonging to GPs of the intervention group. Overall, 1,672 patients (22.9%) of the control group and 1,886 (23.5%) patients of the intervention group received antiplatelet drugs at baseline (P = N.S.). At the end of the follow-up, the number of treated patients was significantly increased in the intervention group (odds ratio 1.99, 95% CI 1.79–2.22) versus the control group. The effect of the electronic reminder was more relevant among those patients with one or more cardiovascular risk factors but without previous cardiovascular diseases (CVDs), compared with those with CVDs. CONCLUSIONS—These findings provide evidence for the effect of an electronic reminder in affecting the prescriptive behavior of GPs.