Aspergillus is a mould fungus commonly found in nature, especially in soil, with over 900 different species. The development of infection is determined by the host's immune status, and the risk of fungal infection increases in conditions where immune suppression occurs for various reasons. In humans, Aspergillus fumigatus is responsible for over 90% of Aspergillus infections, while Aspergillus flavus is responsible for 10% of invasive diseases, Aspergillus niger for 2%, and Aspergillus terreus for a smaller percentage. In cases where an adequate response to treatment cannot be achieved, and with repeated culture positivity, underlying risk factors should be carefully evaluated. In rare cases, infection can also develop in individuals without underlying risk factors. In invasive aspergillosis, different organ involvements are possible, but lung infections are the most common. Aspergillus-related mediastinitis is exceptionally rare. The aim of this article is to present a case of Aspergillus mediastinitis, which is rare in immunocompetent individuals.