BACKGROUND: Adherence to self-care recommendations in heart failure (HF) patients is essential to improve the patients' quality of life, prevent hospital admission, and reduce mortality and morbidity. Nevertheless, poor adherence to self-care recommendations remains to be an extensive problem for HF patients. Thus, the aim was to assess adherence to self-care recommendations and associated factors among HF patients in public hospitals, Addis Ababa, Ethiopia, 2021. METHODS: An institutional-based cross-sectional study was conducted among adult HF patients from February 15 to April 15, 2021, in five public hospitals, in Addis Ababa, Ethiopia. A total of 294 adult HF patients completed an interviewer-administered questionnaire in the Amharic language. The Revised HF Compliance Questionnaire was used to measure the adherence to self-care recommendations of HF patients. Data was collected using the Revised HF Compliance Questionnaire, the Japanese heart failure knowledge scale, the multidimensional scale of perceived social support, and the chronic diseases self-efficacy scale. Study participants were selected through a systematic random sampling technique. Data were entered into Epi-info version 7.1 and then exported to SPSS Version 25 for analysis. Descriptive and logistic regression analyses were performed and the statistical significance of associations between the variables was determined using ORs with 95% CI and p-values < 0.05. RESULTS: Adherence to self-care recommendations among adult HF patients in public hospitals, in Addis Ababa, Ethiopia was 32.70%. Being female (AOR 4.66, 95% CI 1.58-13.67), patients who had high family monthly income (AOR 10.32, 95% CI 2.00-5.13), NYHA class III (AOR: 7.01, 95% CI 2.18-22.57) and class IV (AOR: 6.30, 95% CI 1.01-39.22), who had good self-efficacy (AOR 7.63, 95% CI 2.64-21.97), and who had good knowledge about HF (AOR 3.95, 95% CI 1.56-9.95) were more likely to have good adherence to self-care recommendations, p-value < 0.05. CONCLUSION: This study revealed that 32.70% of adult HF patients had good adherence to self-care recommendations. Factors associated with adherence to self-care recommendations of adult HF patients are sex, family monthly income, NYHA classification, self-efficacy, and knowledge about HF. Therefore, interventions focused on sex, family monthly income, NYHA classification, self-efficacy, and knowledge about HF are required to improve adherence to self-care recommendations of adult HF patients.