There is limited evidence that dipyridamole is generally an effective antithrombotic agent when used alone, nor is there convincing evidence that the combination of aspirin and dipyridamole is more effective than aspirin alone, except perhaps in cerebrovascular disease. There is no consistent evidence to support the routine use of dipyridamole after coronary artery bypass grafting and in patients with occlusive peripheral vascular disease, although these remain common reasons for its use. Dipyridamole is a useful agent in 'pharmacological stress' testing in nuclear cardiology imaging and may be valuable when combined with warfarin in certain patient groups, such as those with prosthetic heart valves. When combined with aspirin, dipyridamole may be of value in the secondary prophylaxis of cerebrovascular disease, although further studies are clearly needed. In a significant proportion of cases, evidence-based medicine cannot support the current widespread continued prescription of dipyridamole in cardiological practice, but the jury is still out on cerebrovascular disease.