Cladosporium species are ubiquitous dematiaceous fungi, widely found in the indoor and outdoor environments. They are considered a frequent source of contamination in laboratory settings. In human pathology, Cladosporium is a main agent of phaeohyphomycosis, known to cause subcutaneous and brain abscess, especially in immunocompromised hosts. The route of disseminated infections is mainly hematogenous after inhalation of the spores. However, a direct inoculation could be possible. We report the first case of a para-aortic abscess with thrombus formation, caused by Cladosporium spp., after a valvular replacement surgery, in an immunocompetent patient. This raises the alarm about the rapid identification of the source of contamination in the operating room, in order to prevent the emergence of further fatal infections.