Alzheimers disease is a disease that occurs with advancing age and is characterized by progressive dementia and neural degeneration. In recent years, it has been stated that insulin deficiency and insulin resistance are associated with neurodegenerative processes in Alzheimers disease. It has been supported by many recent studies that a decrease in the amount of brain insulin and insulin resistance has a role in the accumulation of amyloid beta and hyperphosphorylated tau protein, which are held responsible for the pathogenesis of Alzheimers disease and reduces synaptic pilasticity. For this reason, the definition of Type III diabetes has been used for Alzheimers disease in recent years and has brought a new perspective to the pathogenesis and treatment of Alzheimers disease. In this study, we aimed to discuss the role of insulin deficiency and insulin resistance in Alzheimers etiopathogenesis. For this purpose, current articles related to Alzheimers and Type III diabetes have been reviewed.Keywords: Alzheimers disease, Insulin resistance, Type-3-diabetes.