Patients with type 2 diabetes, but also older patients with type 1 diabetes, are at major risk of cardiovascular morbidity and death. After an acute cardiac event, the prognosis of patients with diabetes is impaired, with clear increases in in-hospital and long-term morbidity and deaths. Both hyper- and hypoglycaemia are deleterious after an acute cardiac event, and the decision to start intravenous insulin is often challenging. Moreover, some antidiabetic treatments have cardioprotective effects, and the onset of an acute cardiac event provides an opportunity to shift to these treatments. The objective of this position statement is to offer practical tools to cardiologists seeking to improve the care of patients with diabetes hospitalized for an acute cardiac event, and to optimize collaboration between cardiologists and diabetologists. After a summary of the evidence for antidiabetic treatments in patients with acute cardiac events, we propose an algorithm to start and adapt intravenous insulin in the most severe patients, and conclude with standard insulin protocols or oral treatments at discharge. We also discuss appropriate antidiabetic treatment of these patients at discharge, based on the main cardiological diagnosis, kidney function and antidiabetic strategies. Finally, situations in which the diabetologist must be consulted are discussed.