OBJECTIVES:  Heart failure(HF) is the second leading cause of death and a serious economic burden of healthcare service in Taiwan. It is recommended to use Angiotensin Converting Enzyme Inhibitor/Angiotensin Receptor Blocker (ACEI/ARB) and beta blockers (BB) for HF treatment as the evidence-based medications. However, by studying National Health Insurance Research Database, the prescribing rates on ACEI/ARB were 49% and 32% on BB, respectively. Guideline-adherent medications (GMs) were underused on HF patients in Taiwan. The aim of this study is to evaluate if the use of GMs of HF treatment in a medical center demonstrates better result, and to explore the necessity of pharmacist intervention. METHODS: P< 0.05 indicated statistical significance. RESULTS: Prescriptions adherent to guideline (group A) shared similar hospitalization period with the non-adherent group (group B) (OR: 0.99, 95%CI：0.43~2.29, P=