Tehran University of Medical Sciences Iranian Journal of Microbiology 2008-3289 17 3 2025 06 02 511 515 Uksim Qadri Department of Microbiology, Sher-i-Kashmir Institute of Medical Sciences, Soura, Jammu and Kashmir, India Sanam Wani Department of Microbiology, Sher-i-Kashmir Institute of Medical Sciences, Soura, Jammu and Kashmir, India Saleem Wani Department of General Medicine, Sher-i-Kashmir Institute of Medical Sciences Sour, Jammu and Kashmir, India Bashir Fomda Department of Microbiology, Sher-i-Kashmir Institute of Medical Sciences, Soura, Jammu and Kashmir, India Umaya Majid Department of Microbiology, Sher-i-Kashmir Institute of Medical Sciences, Soura, Jammu and Kashmir, India Iram Jan Department of Microbiology, Sher-i-Kashmir Institute of Medical Sciences, Soura, Jammu and Kashmir, India Suraiya Mir Department of Microbiology, Sher-i-Kashmir Institute of Medical Sciences, Soura, Jammu and Kashmir, India 2024 07 08 2025 03 28 Considerable information is available about the acute respiratory symptoms of influenza A and B. However, rarely, these viruses can adversely affect the cardiovascular system. Few cases of pericardial effusion and cardiac tamponade due to the Influenza virus have been reported. To the best of our knowledge, we present the first case of a 23-year-old unvaccinated woman having concurrent influenza A and B infection manifesting as pericardial effusion and cardiac tamponade. The patient was treated with oseltamivir 75 mg, resulting in significant clinical improvement. This case emphasizes the importance of considering influenza as a possible cause of cardiac tamponade. https://ijm.tums.ac.ir/index.php/ijm/article/view/4896 https://ijm.tums.ac.ir/index.php/ijm/article/download/4896/1793