Objective: Different metal and metal oxide nanoparticles have been found to have antimicrobial capabilities but the exact mechanism is still not clearly identified. However, there are some hypotheses, including 1. destruction of microbial cell wall, 2. change in selective permeability of cell membrane, 3. effect on mitochondrial respiratory system, and 4. destruction of DNA and cell proteins. Past research showed that CuO (copper oxide) and SiO2 (silicon dioxide) nanoparticles had antibacterial effect on S.aureus and B. subtilis, but fungicidal activity of these compounds is not clear. The aim of this study was to evaluate the effect of these two nanoparticles on growth of Candida albicans ATCC 10231. Materials and Methods: Different (1.4- 3000 mg/L) concentrations of SiO2 nanoparticles (10nm, 600 m2/g, from Lolitech, Germany) and CuO nanoparticles (60nm, 80 m2/g, from Lolitech, Germany) were prepared and were exposed to Candida albicans suspension (ATCC 10231) cultured for 2 days at room temperature, the turbidity of which was adjusted to 0.5 McFarland. After 6, 12, 24, and 48 hours of incubation at 37 °C, its light absorption at 405 nm wavelength, and also its growth rate were determined. For comparison with the control, t-test was used for both different concentrations and different incubation times. Results: This study showed that during the 48-hours incubation at 37 °C with 1000 mg/L of CuO nanoparticles, maximum inhibition has been achieved. Also at the same incubation time with 0.9 mg/L of SiO2 nanoparticles, the highest inhibitory effect was observed. T-test revealed significant differences (p=0.01) between the control sample and these concentrations at 48 hours of incubation. Conclusion: It seems that antifungal effect of SiO2 is better than CuO, and would probably be useful for in vivo application, if its safety will be studied and proved.