Purpose: The purpose of this study was to explore socio-demographic, clinical and psychological factors associated with medication adherence among patients with chronic heart failure (CHF). Methods: In a cross-sectional survey, 133 patients with CHF who had visited a clinic located in Seoul participated. Medication adherence (MA) was measured using a single item visual analogue rating scale (VAS). Barriers and attitudes toward adherence, and depression were measured using a structured questionnaire. Medical records were reviewed to identify their clinical characteristics. Multivariate logistic regression was performed identify factors affecting medication adherence. Results: About one third of participants (31.1%) reported their MA as 100%. Overall attitudes on MA were highly positive and 49 (36.8%) of participants were depressive. MA was associated with significantly barriers (p<.001), attitudes (p<.001), age (p<.001), and duration of disease (p<.001). The high adherent group had significantly less barriers than other groups (OR=.389, p=0.02). Conclusion: This study indicates that barriers and attitudes toward MA were the most important factors affecting their adherence to HF medication. To improve MA for patient with CHF, the nursing strategies which can lead poor adherent patients to their optimal level should be developed.