AbsrtactBackground: Candidiasis is the most common fungal infection in human and warm-blooded animals. Candida albicans, is an opportunistic pathogen in immune suppressed hosts, like HIV infected and under chemotherapy patients. Since, antifungal drugs are limited and challenged by resistance. Thus discovering agents with antifungal properties and minimum side effects and toxicity is essential. Nano-agents such as metal oxide nano-particles have unique properties such as high surface to volume ratio that introduce them as appropriate antimicrobial agents. Materials and Methods: In this experimental study, antifungal effects of 4 nano-metal oxides; magnesium oxide, zinc oxide, silicon oxide and copper oxide (MgO, SiO 2 , ZnO and CuO) were investigated in vitro against Candida albicans and compared with amphotericin B. Solution acetic acid was used for preparing nanoparticles suspensions. Minimum inhibitory concentration (MIC) and minimum fungicidal concentration (MFC) of these nano-particles were evaluated. Results:The results showed that MIC of nano-MgO and nano SiO 2 was greater than 3200 µg/mL, but MIC and MFC of nano-ZnO was recorded 200 µg/mL and 400 µg/mL, respectively. The MIC and MFC of nano-CuO was 400 µg/mL. The MIC and MFC of amphotericin B was 0.5 µg/mL and 2 µg/mL, respectively. Conclusions: It is concluded that, ZnO and CuO nanoparticles have anti C. albicans properties and may be used in treatment of infections caused by this fungus that should be investigated in vivo.