Aim: This study was conducted to determine the level of hopelessness, health behaviors, and quality of life of the patients with chronic heart failure under the age of 65 years and the correlation of these factors. Methods: This descriptive and cross-sectional study was carried out with 143 patients in the Cardiology Clinics of a tertiary hospital and a public hospital. Data were collected using “Patient Information Form,” “Beck’s Hopelessness Scale,” Heart Failure Health Behaviors Scale, and Minnesota Living with Heart Failure Questionnaire. Parametric and nonparametric tests as well as mean, standard deviation, and percentages were used to evaluate the data. Results: The mean age of the patients was 57.8 ± 8.31 years and 70.6% of them were males, 32.2% of them were treated with the diagnosis of heart failure for 10 years and more. The total scores of the patients on the scales were 6.90 ± 4.66 for hopelessness, 99 ± 12.26 for health behaviors, and 42.75 ± 21.69 for quality of life. A positive correlation was found between hopelessness and quality of life (P < .05). The patients’ quality of life varied depending on gender, New York Heart Association functional classification, and hospitalization within the last year (P < .05). Conclusion: As the level of hopelessness of the participants increases, the quality of life decreases. Certain socio-demographic and disease characteristics of the patients influence the health behavior, the level of hopelessness, and the quality of life. As a result, it is recommended that in order to increase the quality of life, the patients should be followed up regularly of the psychosocial well-being, the necessary interventions should be planned accordingly, and patient education on the importance of self-care and health behaviors in the management of the disease should be organized.