Objective: Health literacy (HL) has been recognized as an important concept in patient education and disease management for heart failure (HF). However, previous studies on HL have focused predominantly on the relationships between functional HL (the ability to read and write), comprehensive HL including the ability to access information (communicative HL), and the ability to critically evaluate information (critical HL). Self-care behavior has not been evaluated. This study determined the relationship between functional, communicative, and critical HL and self-care behavior in HF patients. Methods: Cross-sectional analysis of the data was completed for HL, HF-related knowledge, and HF-related self-care behaviors. Sociodemographic and clinical characteristics were also assessed. Multivariate linear regression analysis was used to estimate the associations between literacy and self-care behavior. Results: 249 patients with HF were assessed (mean age, 67.7 +/- 13.9 years). Patients with low HL had poorer knowledge and self-care behavior than those with high HL. Critical HL was an independent determinant of self-care behavior (s beta = -0.154, P = 0.027). Conclusions: Critical HL was independently associated with self-care behavior in HF patients. Practice implications: Effective intervention should be developed to improve patient skills for critically analyzing information and making decisions. (C) 2016 Elsevier Ireland Ltd. All rights reserved.