The diagnosis of a mycosis is often established through a biopsy, which allows to differentiate invasive and non-invasive lesions, and also to identify hyaline and dematiaceous fungi. However, pigmented fungal elements that do not correspond to dematiaceous fungi, which we have called pseudodematiaceous, can occasionally be present in biopsies. Herein, we present 2 cases of mycosis caused by pseudodematiaceous fungi in rhinosinusal biopsies. A new classification for fungi identified in biopsies is proposed, dividing them into 3 groups: hyaline, dematiaceous, and pseudodematiaceous.