2023-04-052023-04-05202124233439https://doi.org/10.18502/cmm.7.4.8409http://146.190.124.33/handle/123456789/6255Background and Purpose: Histoplasma capsulatum is the cause of a prevalent fungal disease in certain regions in the United States of America, like Ohio and the Mississippi River. Its clinical manifestations range from asymptomatic to life-threatening diseases, according to the immune system. A definitive diagnosis is made by biopsy.Case report: Two middle-aged brothers presented with a nine-day history of severe progressive dyspnea. Both were living in Cincinnati, Ohio, and encountered bird droppings 7 days prior to symptoms while working on a roofing project. It should be mentioned that they were not wearing masks. After extensive testing, they were diagnosed with acute pulmonary histoplasmosis. Both were successfully treated with azole-derivative fungal therapy. Conclusion: This is the first case of histoplasmosis acquired through occupational exposure related to roofing and is unique given the two patients were siblings. © 2021, Published by Mazandaran University of Medical Sciences on behalf of Iranian Society.enginfo:eu-repo/semantics/article