Inpatients with heart failure take a number of high-risk drugs such as anti-thrombotic and anti-arrhythmic drugs, in addition to other drug types, including diuretics and cardioprotective agents. Pharmacists should support the pharmacological management of these patients by evaluating their clinical condition and laboratory data, due to the frequency of renal failure. Furthermore, it is known that poor adherence to a drug regimen is one of the aggravating factors for heart failure. It is necessary to conduct regular patient education to facilitate early hospital discharge and to prevent the recurrence of heart failure. In Chiba University Hospital, a single pharmacist is in charge of both the cardiac care unit (CCU) and the cardiovascular ward. In the course of a patient's hospital stay, from admission to discharge, the pharmacist performs various duties such as evaluating and proposing a medication plan after checking the patient's regular medications, conducting patient education, promoting appropriate prescriptions, overseeing the preparation of injection drugs, and providing drug information to medical staff. There are many cases in which avoidance of drug interactions or overdose, in order to prevent renal failure, is needed. Thus, pharmacists play important roles in the management of patients with heart failure by ensuring the efficacy and safety of each patient's drug therapy.