Tehran University of Medical Sciences Journal of Medical Bacteriology 2251-8649 13 4 2025 12 12 90 94 Sheetal Goenka Govind Ballabh Pant Institute of Postgraduate Medical Education and Research Wanshisha Wanswett Govind Ballabh Pant Institute of Postgraduate Medical Education and Research Shivani Tyagi Govind Ballabh Pant Institute of Postgraduate Medical Education and Research Poonam Loomba Govind Ballabh Pant Institute of Postgraduate Medical Education and Research Manisha Jain Govind Ballabh Pant Institute of Postgraduate Medical Education and Research Abha Sharma Govind Ballabh Pant Institute of Postgraduate Medical Education and Research 2025 09 19 2025 10 26 Background:   Nasal carriage of Staphylococcus aureus, particularly methicillin-resistant strains, poses significant risks for healthcare-associated infections in surgical wards. This study aimed to determine the prevalence of methicillin-resistant S. aureus (MRSA nasal carriage among patients in cardiothoracic and neurosurgery units. Methods:   This prospective cross-sectional study was conducted from January to July 2025 in cardiothoracic and neurosurgery wards of a tertiary care hospital. Nasal swab samples were collected from 100 patients and processed for bacterial identification and antimicrobial susceptibility testing using standard microbiological methods. Results:   Among 100 nasal swab samples, 36 (36%) yielded Staphylococcus aureus growth, while 64 (64%) showed coagulase-negative staphylococci (CoNS) or gram-negative bacteria. Of the 36 S. aureus isolates, antimicrobial susceptibility testing revealed varying resistance patterns, with implications for infection control protocols in surgical settings. Conclusion:   The study provides baseline data on S. aureus nasal carriage rates in high-risk surgical wards, emphasizing the need for targeted screening and decolonization protocols to prevent healthcare-associated infections. https://jmb.tums.ac.ir/index.php/jmb/article/view/620