Fungal rhinosinusitis refers to a wide variety of conditions caused by fungal infections of the paranasal sinuses. Allergic fungal rhinosinusitis and sinus fungus balls are mostly noted in healthy individuals. Aspergillus species are supposed to be the most common etiologic agents of the disorder, but melanized fungi also occur, and these potentially are able to lead to fatal dissemination into brain parenchyma. We report on a case of fungus ball in a 20-year-old female with refractory chronic rhinosinusitis (RCRS) and bronchial asthma due to the black yeast Exophiala oligosperma which was confirmed by mycological and molecular (sequences of ITS rDNA) investigations. Exophiala oligosperma has previously not been reported to cause fungus balls or invasive fungal rhinosinusitis. Patient underwent functional endoscopic sinusitis surgery and the hypertrophic mucosa was removed completely. Without antifungal therapy, successful cure was achieved after spray therapy with corticosteroids for 1 month, without any relapse after a 6 month-follow up.