<b><i>Background: </i></b>Invasive infections caused by <i>Aspergillus fumigatus </i>as well as <i>Pneumocystis</i> pneumonia are serious and often lethal diseases in severely immunocompromised patients. <b><i>Case Report: </i></b>We report on a rare case of a pulmonary coinfection of <i>Pneumocystis jirovecii</i> and <i>Aspergillus fumigatus</i> in a 59-year-old female patient with a history of astrocytoma treated with high doses of corticosteroids and a subsequent CD4 lymphocyte count of 30/µl. <b><i>Conclusion: </i></b>A heightened clinical awareness and a stringent and accurate diagnostic work-up encompassing diagnostic tools to detect even coincident fungal infections is crucial for sufficient and early antifungal treatment in immunocompromised patients with lung infiltrates.