Cognitive dysfunction, including mild cognitive impairment, Alzheimer′s disease and dementia, is increasingly recognized as significant comorbidities or complications of type 2 diabetes mellitus (T2DM), disrupting glycemic management. This paper reviews the association between T2DM and cognitive dysfunction and glycemic control, screening and diagnosis of risk factors, T2DM management in patients with cognitive dysfunction (considering advanced age and frailty in older adults), and emerging preventative therapies. Satisfactory glycemic management and early cognitive testing are essential components of T2DM management, and persona-lized strategies should be implemented, including patient education, glycemic monitoring, and appropriate dietary and medication adjustments based on daily conditions (including physical exercises).