This review mainly deals with scientific data related to sporadic Alzheimer’s disease (AD) particularly related to diabetes mellitus (DM). AD is divided into sporadic AD and familial AD. It is known to be the most common cause of dementia. Sporadic form of AD results from multiple etiologic factors including metabolic, environmental and genetic factors. DM linked AD is known to be one of major challenges to health care system in these days. Both type 1 and type 2 DM is strongly related to cognitive impairment and known to be a major risk factor in the development of probable Alzheimer’s disease. In this review, the various mechanisms involved in the development of neuronal degeneration associated with chronic hyperglycaemia are discussed.