Key Clinical MessageAs only early diagnosis, prompt surgical intervention, and appropriate antibiotic therapy can decrease clostridial MAA mortality rate; keeping in mind a broad differential diagnosis in a patient with sepsis and unusual vascular symptoms is important.AbstractMycotic aortic aneurysm (MAA) is an infrequent but very consequential condition characterized by the pathological disruption of the aorta due to infection. Clostridium perfringens is a bacterium that falls under the taxonomic classification of the genus Clostridium. Although mycotic aneurysm is often not commonly linked with this infection, there are instances when it may function as a causative agent for MAA. Timely diagnosis and thorough therapeutic techniques, including surgical intervention and quick administration of appropriate antibiotics, can potentially reduce the mortality rate associated with clostridial MAA. In this study, we presented a clinical report detailing the diagnosis of a mycotic aneurysm caused by C. perfringens in the thoracic aorta in a 66‐year‐old male patient with a history of diabetes mellitus and a recent prostate biopsy. Furthermore, we discussed the surgical approach and overall management strategy to address this case.