Background: Candida albicans is the fourth common cause of chronic fungal infections that cause both mucosal and deep tissue infections. Nowadays, mortality and morbidity due to C .albicans infections via medical devices, such as catheter and implants, are increasing. Therefore, finding new methods of combating such infectious agents seems necessary. In this study antifungal effects of titanium dioxide nanoparticles and photocatalyst TiO2 nanoparticles on C .albicans biofilms were investigated. Materials and Methods: In this experimental study, TiO2 nanoparticles were synthesized and exposed to UV ray with 370 nm wavelength. Biofilms of C. albicans were developed on flat-bottomed 96-well microtiter plates, and antifungal effects of TiO2 and photocatalyst TiO2 nanoparticles were evaluated. Data were analyzed by t-test using SPSS software. Results: MIC50 of photocatalyst TiO2 nanoparticles was 1.9 µg/ml and its MIC90 was 2.74 µg/ml while MFC was determined to be 3.37 µg/ml. Biofilms inhibitory concentration of TiO2 nanoparticles, photocatalyst TiO2 nanoparticles, and fluconazole for susceptible strains were 5.14, 4.54, and 4 µg/ml, respectively. These values for the fluconazole resistant strains were 5.35, 4.88, and 8 µg/ml, respectively. Conclusion: Photocatalyst TiO2 nanoparticles showed a suitable antifungal property against C. albicans biofilms compared with fluconazole. Thus it can be a new strategy in prevention of fungal biofilms, especially those formed on the surface of medical devices.