Background: Acceptance of illness is crucial in chronic diseases such as heart failure (HF), which persists throughout a patient’s lifetime, significantly affecting adaptation to treatment and lifestyle modifications. While the relationship between the acceptance of illness and the quality of life in HF patients is well-documented, its correlation with comfort levels remains unexplored. Aim: This study aimed to explore the correlation between acceptance of illness and comfort levels among HF patients. Methods: This descriptive study included 106 HF patients from the cardiology service of a university hospital. The study data was collected between November 2019 and February 2020 through face-to-face interviews using a personal information form, the Acceptance of Illness Scale, and the General Comfort Questionnaire. In the analysis of descriptive statistics, various statistical tests were employed, including Student’s t-test, One-Way Analysis of Variance (ANOVA), Welch’s test for assessing group variances, Bonferroni test, Games-Howell test, and Pearson’s correlation coefficient for analyzing pairwise comparisons. Results: The study found the average age of the patients to be 67.9 ± 11.6 years. Among these patients, 55.7% were male, the majority (68.9%) were married, nearly half (44.3%) had completed primary education, and a significant majority (73.6%) were not employed. The mean scores for the Acceptance of Illness Scale and the General Comfort Questionnaire were 18.8 ± 7.75 and 2.6 ± 0.40, respectively. Patients who were non-literate, those belonging to low-income and high-income groups, and those who had been diagnosed with HF for four years or longer, exhibited lower mean scores on the Acceptance of Illness Scale compared to other groups (P<0.05). A moderate positive correlation was observed between the total scores of the Acceptance of Illness Scale and the General Comfort Questionnaire (r=0.517, P<0.001). Conclusion: The study concluded that an increase in the level of illness acceptance among HF patients was associated with an increase in their comfort levels. Consequently, it is recommended that the acceptance of disease in HF patients and their needs concerning environmental, physical, sociocultural, and psychospiritual comfort be regularly assessed in hospital settings. This assessment should inform the planning and implementation of tailored nursing interventions, taking into account the factors that influence these needs.