Background/Aims: Advance directives (ADs) in Korean patients with heart failure (HF) and the associations of attitude towards ADs and HF prognosis with ADs were initially assessed using the model of the Korean-Advance Directive (K-AD). Methods: Twenty-four patients with HF (age, 67.1 years; men, 58.3%; ejection fraction, 35.9%) participated. A pilot test to evaluate the feasibility of ADs and the possible associations of attitudes towards ADs and prognosis with end-of-life treatment preferences among patients with HF was conducted. Results: Fifteen patients (62.5%) completed the K-ADs. The major reason for incomplete K-AD was knowledge deficit. Patients valued “comfortable death” the most (45.4%), followed by “giving no burden to the family” (13.6%). Among treatment preferences, hospice care was preferred by the majority (66.7%), while cardiopulmonary resuscitation (CPR) was preferred by the minority (31.8%). Children (50.0%) were mostly appointed as a proxy, followed by the spouse (33.3%). More patients with moderately positive attitudes completed the K-ADs than their counterparts (70.0% vs. 57.1%). The 5-year survival rate was 69.2%; the patients who preferred CPR had a higher survival rate (70.6% vs. 68.5%) whereas those who preferred hospice care had a lower survival rate than their counterparts (70.7% vs. 75.2%). Conclusions The findings support the feasibility of the K-AD model, with a high acceptance rate in two-thirds of the sample. Further studies are warranted to investigate whether treatment preferences are associated with attitude towards ADs and/or HF prognosis using larger sample size.