OBJECTIVE： To explore the role of clinical pharmacists participating in the prevention and treatment of sotalol-induced QT prolongation in aged patient with heart failure. METHODS： Clinical pharmacists participated in the treatment for a aged patient with heart failure， and assisted physicians to identify and assess the risk of sotalol-induced QT prolongation. According to the clinical symptoms and laboratory indexes， it was suggested to continue to use sotalol for antiarrhythmic， adjust the hepatoprotective drug， given pharmaceutical care of ECG， electrolyte level monitoring， drug education and so on. RESULTS： Physicians adopted the suggestions of clinical pharmacists to relive the illness without malignant arrhythmia and discharged after 11 d. CONCLUSIONS： The patient with heart failure should be dominated by improving cardiac function and maintaining hemodynamic stability； combined with related guidelines and documentation， clinical pharmacists can assist physicians to identify the drug that induced QT prolongation， asses the risk of torsades de pointes ventricular tachycardia and other bad consequences， develop and optimize the regimen and strengthen pharmaceutical care to ensure the safe and effective treatment.