Acute ischemic stroke is a leading cause of death and severe disability in industrialised countries and also in many developing countries. An excessive amount of free radicals is generated during cerebral ischemia, which significantly contributes to brain damage. Therefore, an increasing interest has been devoted to the potential benefits of antioxidant compounds in ischemic stroke patients. In this review, we examined the most relevant observational studies concerning the relationship between dietary antioxidants and ischemic stroke as well as clinical trials investigating the effects of single or multiple antioxidant supplementation in the prevention or treatment of acute ischemic stroke. Furthermore, we reviewed the most promising antioxidant compounds, i.e. dehydroascorbic acid, alpha-tocotrienol, gamma-tocopherol, flavonoids, resveratrol and gingko biloba, tested in animal models of acute ischemic stroke. Finally, we carefully evaluated the reasons for the discrepancy between experimental and clinical studies, and provided recommendations to improve the translation of the results obtained in animal models to patients with acute ischemic stroke.