Introduction: Heart failure (HF) is a complex and common clinical syndrome whose symptoms are caused bystructural or functional disorders in the heart. Although several studies have been conducted to identify thefactors associated with the hospital readmission of patients with HF, statistics still show a high readmission rate in these patients. Therefore, it is necessary to conduct further studies to identify the factors that are effective inreducing the readmission rate and preventing the cost burden on the health system and patients.Objective: This study aims to investigate the factors associated with the 30-day readmission rate of patientswith HF in Iran. Materials and Methods: This is a retrospective single-center study, which was conducted on 312 patientswith HF admitted to a hospital affiliated to Isfahan University of Medical Sciences, Isfahan, Iran from April toSeptember 2019. The medical records of these patients were reviewed and followed up for 6 months after the initial admission to assess the rate of 30-day readmission to the same hospital. The information was collected using a researcher-made form that surveyed sociodemographic characteristics, clinical characteristics, commondrug treatments and discharge conditions. The data were analyzed using inferential statistics, including t-test,chi-square test/Fisher’s exact test and multiple logistic regression analysis. Results: Among patients, 181(58%) were over 65 years of age, 65.7% were male and more than 88% were married. The overall 30-day readmission rate was 7.4% (23 out of 312), and the rate of over 30-day readmission was 17% (53 out of 312). The readmission rate in men (8.8%) was higher than in women (4.7%), but this difference was not statistically significant. The readmission rate in unemployed patients (21.4%) was higherthan in patients with other occupations (0.9-3.9%). The results of logistic regression showed that as bodymass index increased, the likelihood of readmission decreased (OR=0.84, 95% CI, 0.74, 0.96, P=0.001), and the likelihood of readmission in patients who received diuretic therapy was 4.24 times higher than in those who did not receive diuretics (OR=4.24, 95% CI, 1.02, 1.17, P=0.047). Conclusion: The follow-up of patients with HF treated with diuretics, as well as those with high body massindex are needed due to their higher risk of hospital readmission. Developing a post-discharge care plan forthese patients can be effective in reducing their 30-day readmission rate.