This cross-sectional analytical study investigated the relationships between mental health literacy and stress, depression, and anxiety in chronic heart failure patients within a cardiac outpatient department. A simple random sample of 116 patients was included. Data were collected using questionnaires covering participant demographics, clinical information, and mental health aspect. The content validity (IOC) ranged from 0.67 to 1, and reliability, assessed using Cronbach's alpha coefficient, was 0.78 to 0.90. Data were analyzed by descriptive statistics and Pearson's correlation statistics. Findings reveal an average participant age of 60.86±12.98 years, with a male majority (66.38%). Mean scores were: mental health literacy component 184.28±23.38, stress 3.15±2.32; depression 7.83±4.84, and anxiety 52.27±11.58. Significant negative correlation existed between mental health literacy and stress (r = -0.306, p<0.001), depression (r = -0.590, p<0.001), and anxiety (r = -0.574, p<0.001). The study indicated that mental health literacy was at a good level among chronic heart failure patients, demonstrating a negative association with stress, depression, and anxiety. Therefore, cardiac outpatient departments could integrate care management strategies to promote mental health literacy and mitigate stress, depression, and anxiety in these patients.