Objective: This study aimed to examine the correlation between quality of life, depression, anxiety, stress, and spiritual well-being in patients with heart failure and their family caregivers. Methods: This descriptive, correlational study was carried out in a coronary outpatient clinic, located in Ankara between March-October 2018. Sixty patients with heart failure, and 60 family caregivers who providing care for these individuals, a total of 120 participants were included in the study. The Kansas City Cardiomyopathy Questionnaire, the Depression Anxiety Stress Scale, the World Health Organization Quality of Life Short Form, and the Functional Assessment of Chronic Illness Therapy-Spiritual Well-Being Scale were utilized for data collection. The data were analyzed using descriptive and correlational statistics. The Pearson correlation test was used to determine the association between the Kansas City Cardiomyopathy Questionnaire, the Depression Anxiety Stress Scale, the World Health Organization Quality of Life Short Form, and the Functional Assessment of Chronic Illness Therapy-Spiritual Well-Being Scale scores. Results: As quality of life scores increased in patients with heart failure, depression, anxiety, stress scores increased (p<0.05). On the other hand, as quality of life scores increased in patients with heart failure, spiritual well-being scores increased (p<0.05). With regard to family caregivers, as quality of life scores decreased, depression, anxiety, stress scores increased, and spiritual well-being scores decreased (p<0.05). Moreover, as quality of life and spiritual well-being scores of patients with heart failure decreased, depression, anxiety, stress scores of family caregivers increased (p<0.05). Conclusion: This study revealed that as quality of life and spiritual well-being scores decreased, depression, anxiety, stress scores of both patients with heart failure and family caregivers increased. Further education and counseling programs targeting patients with heart failure and their family caregivers are recommended to assess both patients' and family caregivers' psychological health and spiritual well-being.