Onychomycosis is a type of fungal infection caused by dermatomycetes, yeast or filamentous fungi, in which the nail apparatus is affected. Due to the insufficient activity of effective cellular immunity, the nail apparatus tends to be invaded by fungal pathogens when exposed to certain risk factors, being an ideal ecological niche for long-term persistence of fungi. This explains why onychomycosis, as a rule, is chronic infection, proceeding without signs of active inflammation.In the absence of treatment of onychomycosis, there is a significant risk of complete destruction of the nail plate with the involvement of the surrounding skin, as well as the spread of infection, as a rule, due to autoinoculation. The need and possibility of therapy should be considered for each patient with onychomycosis. However, the decision on the choice of methods and a specific drug should depend on a number of individual factors.The article considers the factors influencing the efficiency of topical therapy for onychomycosis. It has been shown that before choosing a therapy for onychomycosis, several factors must be taken into account: the type of pathogen, subtype of onychomycosis, anatomical localization (hands, feet), matrix involvement, the number of affected nails, the thickness of the affected nail plate, and the coexistence of other mycoses in other locations. Topical antifungal drugs contain high concentrations of active substances, but to improve permeability and increase the efficiency of topical therapy, they require the use of auxiliary means (mechanical, instrumental, chemical, physical). According to the results of international studies, the amorolfine molecule demonstrates significant advantages, having the lowest minimal inhibitory concentration for the destruction of onychomycosis pathogens, penetrates deep into the lower layers of the nail even after a single application. Antifungal varnish Amoderm Neo has broad antifungal activity, a minimum spectrum of side effects, is recommended for topical treatment of dermatophytic and non-dermatophytic onychomycoses, complex therapy of onychomycosis and their prevention.