Summary. Alzheimer’s disease (AD) is a complex neurodegenerative disorder characterized by progressive loss of cognitive function and subsequent death. Since the first case of this disease was diagnosed one century ago, much effort has been dedicated to find a cure. However, even though progress has been made in the knowledge of the pathogenesis of this disease, an effective treatment has not been found. Therefore, new approaches are needed urgently. AD patients have an abnormal cerebral vasculature and brain hypoperfusion, and a large body of research, including some from our lab, implicates cerebrovascular dysfunction as a contributing factor to AD. Reducing fibrinogen, a circulating protein critical in hemostasis, provides a significant decrease in the neurovascular damage, blood–brain barrier permeability and neuroinflammation present in AD. These studies implicate fibrinogen as a possible contributor to AD.