Impaired glucose metabolism and its consequence diabetes mellitus is still challenging the health care system worldwide. According to the International Diabetes Federation in 2021, the number of adult people living with diabetes was approximately 537 million and 860 million adults had prediabetes. It is predicted that numbers will rise in the future. Numerous researches have shown that prediabetes and diabetes mellitus are serious risk factors for cardiovascular diseases. Lots of epidemiological evidence figured out that diabetes mellitus is associated with the risk of developing heart failure. Diabetes mellitus is highly prevalent among patients with heart failure. Moreover, several anti-diabetics (anti-prediabetic) medications are contributing their share into developing heart failure by increasing risk of mortality and hospitalization for heart failure. This chapter will discuss the connection between prediabetes, diabetes mellitus, and chronic heart failure.