Stroke is one of the leading causes of death in the United States. The risk of experiencing a recurrent stroke remains elevated for several years after an initial stroke or a transient ischemic attack (TIA), therefore secondary prevention is crucial in reducing the risk of stroke and the complications and costs associated with stroke. Aggrenox, a combination of low-dose aspirin and extended-release dipyridamole, is a new agent that is effective in the secondary prevention of stroke and transient ischemia of the brain. The clinical effect of its two antiplatelet agents are additive and significantly better than either aspirin or dipyridamole alone, although it has not been shown to be more effective than aspirin alone in preventing death. Aggrenox is much more expensive than aspirin alone but has been shown to be more cost-effective. At this point, much of the pharmacologic information concerning this combination agent is based on previous data about aspirin and immediate-release dipyridamole. This combination of aspirin and extended-release dipyridamole may play a significant role in secondary stroke and TIA prevention.