Cardiovascular disease is the leading cause of morbidity and mortality in diabetic subjects. Diabetes, independently of the mechanism, is associated with an increased risk of left ventricular hypertrophy, left ventricular dysfunction and coronary artery disease. B-type natriuretic peptide (BNP) is a cardiac neurohormone predominantly released from the cardiac ventricles in response to left ventricular volume expansion and pressure overload. Numerous studies have shown that BNP levels are elevated in asymptomatic or symptomatic left ventricular dysfunction, hypertrophy and coronary artery disease. BNP testing plays an important role in the screening and diagnosis of left ventricular dysfunction by improving the performance of non-specialist physicians in diagnosing heart failure. In clinical practice, BNP testing is best used as a 'rule out' test targeted to patients at high risk for left-ventricular dysfunction, such as those with diabetes. Studies are needed to establish if this promising biological tool, in the next future, would assist the management of diabetic patients.