[en] The misdiagnosis of onychomycosis delays the proper treatment of the nail condition. Nail histomycology refers to the microscopic examination of histologic sections prepared from nail clippings for the purpose of detecting the presence of fungi. This laboratory method is the most sensitive procedure for the diagnosis of onychomycosis. It allows for the visualization of the precise location of the invasive fungus inside the nail apparatus. The method also distinguishes various shapes of the fungal cells, in particular filamentous fungi, yeasts, conidia, and sporodochia. The correct diagnosis provided by histomycology combined with culture not only allows for more efficient expenditure of funds and services but also is important for the timely alleviation of the disorder.