The common adverse reactions of liraglutide are hypoglycemia and gastrointestinal reactions. This case reports a patient with type 2 diabetes mellitus who had an increase in ventricular premature beats after using liraglutide and a decrease in ventricular premature beats after stopping liraglutide, suggesting that clinicians should rule out the possibility of drug-related adverse reactions when using liraglutide in the treatment of diabetes mellitus complicated with coronary heart disease and arrhythmia.