Type 2 diabetes (T2D) and its related neurodegenerative complications greatly pose a serious health and economic burden. In recent years, neurofilament light (NfL) has been proved to be as a biomarker of neurodegeneration, and the levels of plasma NfL were found to be associated with clinical staging of diabetes mellitus and cognitive decline. In this review, we indicate that the level of NfL in blood may be a valuable clinical tool to distinguish the normal population, pre-diabetes and diabetes patients. In addition, NfL levels of diabetic