Alzheimer's disease is a neurodegenerative disorder with no cure and not completely understood mechanisms. This devastating disease is one of the main causes of dementia in elderly people worldwide. Among different mechanisms of neuronal death associated to Alzheimer's disease, oxidative stress can be considered as one of the most studied. Several data from literature in this field have shown that oxidative stress seems to be a critical step in the neurodegenerative course of the disease. Clinical trials using antioxidants have described conflicting results, some of them supporting the importance of the use of antioxidant compounds to ameliorate disease's symptoms and the others showing negative results in terms of beneficial effects of antioxidant therapy in the disease progression.