Health literacy is important for the management of chronic cardiovascular diseases. Comprehensive studies related to health literacy of cardiac patients are limited. The aims of this study were to determine the determinants of health literacy and its effects on patient outcomes in cardiology patients. The European Health Literacy Survey Questionnaire (HLS-EU-Q- 47 items) was applied to 530 patients who presented to cardiology polyclinics of a university hospital in Ankara. Correlation coefficients, univariate and multi-linear regression analyses were used in the study. Determinants of health literacy were sex, education level, place of residence and perception of social status (p < .05). Although adjustments were made based on relevant control variables in multivariate analyses, health literacy was found to affect 14 of 26 patient outcomes within the scope of the study (p < .05). Higher education level and perception of social status, residing in the city center and being female were among the determinants of high health literacy. Higher health literacy was associated with more positive patient outcomes. Health literacy affected health behaviors and risks, drug use habits, health status, use of preventive health services and patient satisfaction.