Résumé : Background and Purpose: The European Stroke Prevention Study was a multicenter trial comparing the effect of a combination of 75 mg dipyridamole and 330 mg acetylsalicylic acid three times a day with the effect of a placebo in the prevention of stroke or death in 1,861 patients after one or more episodes of recent transient ischemic attack or cerebral infarction. Methods: The present study represents a secondary analysis of the efficacy of study medication in diabetic (n=216) and nondiabetic (n=1,645) patients. Results: The risk of end point events was greater in diabetic than in nondiabetic subjects. Total end point reduction in individuals receiving the combination of dipyridamole and acetylsalicylic acid was 39% in nondiabetic subjects and 23% in diabetic subjects in the explanatory analysis, and the reduction in the risk of stroke was 48% and 32%, respectively. However, a statistically significant reduction of risk was obtained only in nondiabetic subjects. Conclusions: The combination of dipyridamole and acetylsalicylic acid appeared to be more effective in nondiabetic subjects than in diabetic subjects in the prevention of death and stroke although the low number of diabetic patients may at least in part explain this result.