O Oral candidiasis is an oral infection caused mainly by C. albicans. Chitosan is a natural polymer made from the reaction between crustacean shell and sodium hydroxide alkali. Recent studies showed that the polycationic nature of chitosan is responsible for its antifungal properties. Aim: to investigate the inhibitory effects of chitosan on the growth of C. albicans in vitro on patients with oral candidiasis. Method: This study was conducted using experimental tube dilution method. Chitosan nanoparticles was prepared using 0.2% chitosan solution with drops of tripolyphosphate under continuous stirring of homogenizer. Nanoparticles was then diluted into Saboraud Dextrose Broth in 4 different tubes. Each tube contains 1 to 4ml of chitosan nanoparticles. In this study nystatin and distilled water was used as positive and negative control respectively. After 24 hours of incubation, mixture of media, chitosan, and fungal was spread onto SDA for Candidal colony calculation. Results: A significant decrease in candidal count (P < 0.05) was found with the use of chitosan nanoparticles. An optimum volume of 3ml, concentration 2.4mg/ml, was found to have the most effective antifungal activities with average candidal count of 50. Discussion: Positively charged chitosan particles interact with negatively charged fungal cell wall thus increasing its permeability resulting in cellular leakage. Nano-sized chitosan particle has a greater inhibitory effect on C. albicans. Conclusion: Chitosan nanoparticles can inhibit the growth of C. albicans up to the normal oral flora population making it a good candidate as an alternative oral candidiasis treatment.