Background: Infective endocarditis (IE) represents a significant public health concern as it is associated with elevated morbidity and mortality rates, posing substantial challenges for healthcare systems in terms of prevention, diagnosis, and management Aim: The study aimed to assess nurses’ performance regarding care of patients with acute infective endocarditis. Design: Descriptive research design was utilized. Setting: The study was carried out in Coronary Care Unit at Benha University Hospital. Sample: Convenient sample of (50) nurses. Tools: Two tools were used, Tool (1): Self-administered questionnaire to assess nurses' knowledge regarding acute infective endocarditis, tool (2): Observational checklist to assess nurses' practice regarding acute infective endocarditis patients. Results: 80% of studied nurses had unsatisfactory level of total knowledge regarding acute infective endocarditis and also, 84.4% of studied nurses had unsatisfactory level of total practice regarding care of patient with acute infective endocarditis. Conclusion: The nurses' knowledge and their practice were unsatisfactory regarding acute infective endocarditis. There was a positive correlation between total knowledge and total practice as evidenced by r(p)= 0.597 (