Deep-seated mycosis usually occurred in severe immunocompromised patients and is sometimes fatal. Hence, chronic fungal infection occurred in the patients with mild to moderate immunocompromised status and persists for longer period. Biofilm formation is one of the factors related to persisting infection of Candida spp. Biofilm formation resists to the antifungals in catheter-related Candida infection and selection of appropriate antifungals will be an important key to achieve good outcome. Although azoles possessed excellent antifungal activity against planktonic Candida spp., they show lower activity against biofilm-formed Candida spp. Overexpression of efflux pump of Candida spp. is reported to be involved in lowered activity of azoles. Amphotericin B, liposomal amphotericin B, and micafungin however, are expected to have high antifungal activity against biofilm-formed Candida spp. Recently, Aspergillus is also reported to possess potential of forming biofilm. Biofilm formation of Aspergillus is considered to be related to pathogenesis of chronic pulmonary aspergillosis. General antifungals are not highly active to biofilm-formed Aspergillus as same as Candida, and only amphotericin B and its liposomal formulation are expected to be effective in vitro.