BACKGROUND The ultrastructure of different fungi have been described in recent literature; however, few reports have concerned dermatophytes. METHODS Fine structure of Trichophyton violaceum was observed using electron microscopy. RESULTS Hyphae appeared as branched segmented filaments with a cell wall consisting of two layers. Thin electron dense plasma membrane was evident continuous with the inner surface of the cell wall. Septal walls with central pores and a uniform electron opacity plugs were seen. The hyphae were multinucleated and the cytoplasm contained endoplasmic reticulum, mitochondria, and vacuoles. CONCLUSIONS Although these findings showed ultrastructural similarities of the cell wall with Microsporum canis, Microsporum gypseum and Microsporum audouinii, there were some points of difference in the ultrastructure of the hyphae in Epidermophyton floccosum, and in the mitochondria of Trichophyton mentagrophytes as described by other investigators.