Tehran University of Medical Sciences Iranian Journal of Public Health 2251-6085 50 11 2021 10 16 2332 2336 Mohammad Reza Khalilian Department of Pediatric Cardiology, Mofid Children Hospital, Shahid Beheshti University of Medical Sciences, Tehran, Iran Ali Norouzi Pediatric Respiratory Diseases Research Center (PRDRC), National Research Institute of Tuberculosis and Lung Diseases (NRITLD), Shahid Beheshti University of Medical Sciences, Tehran, Iran Hassan Zamani Department of Pediatric Cardiology, Shahid Beheshti University of Medical Sciences, Tehran, Iran Seyed Khalil Forouzan Nia Department of Cardiovascular Surgery, Erfan Niayesh Hospital, Tehran, Iran Somayyeh Noei Teymoordash Department of Obstetrics & Gynecology, Iran University of Medical Sciences, Tehran, Iran 2020 12 11 2021 03 06 Hydatid disease is a parasitic infection caused by Echinococcus granulosus. Cardiac involvement is rare especially without liver and lungs tissue involvement. We describe a 12-year-old male patient referred to Mofid Children's Hospital, Tehran, Iran in Jul 2020 due to chronic pericardial effusion and suspected tuberculosis infection from Afghanistan. Echocardiography revealed a cystic lesion in the interventricular septum. Thoracic and abdominal computed tomography showed no similar cystic lesion in the lungs and liver. The patient underwent open-heart surgery for cystectomy and medical treatment with albendazole. Histological examination confirmed hydatid cyst diagnosis. The patient was discharged in good condition and oral albendazole was continued. https://ijph.tums.ac.ir/index.php/ijph/article/view/23153 https://ijph.tums.ac.ir/index.php/ijph/article/download/23153/7420