Paracoccidioides are dimorphic fungi.

In its mycelial form, Paracoccidioides species appear as thin septated hyphae with occasional chlamydospores and conidia. 

In the yeast form, Paracoccidioides species are characterized by oval or round budding yeast cells of varying sizes (4 to 40 microns). The typical appearance is that of a large mother cell surrounded by multiple budding daughter cells (blastoconidia), often called a "pilot's wheel" . When the mother cell has only two budding cells, it may resemble a "Mickey mouse head."