Introduction: The use of removable orthodontic appliances which poorly maintained, especially in the acrylic base components, will increase the number of Candida albicans colonies. To maintain an acrylic base of removable or- thodontic appliances we can soak it in herbal substance such as Aloe vera extract. This extract contains of Tanin, Saponin and antifungal. The objective of this study was to determine the effectiveness of Aloe vera extract on the number of Candida albicans colonies on Acrylic Base of Removable Orthodontic Appliances. Methods:This research used 24 samples divided into 5 groups, consisting of 2 control groups: 0.2% aquadest and chlorhexidine gluconate 0,2% and 3 treatment groups: Aloe vera extract concentrations of 25%, 50%, 75%, 100%. The final result is cal- culated the number of Candida albicans colonies using a colony counter. Results: Oneway ANOVA test showed that there were significant differences between the treatment group and the control group as a whole (p <0.05). The results of the Pearson correlation test showed a value of -0.902 indicating that the higher concentration of Aloe vera extract, the lower number of Candida albicans colonies. The results of the Regression test showed a value of 0.814 indicating the effect of the concentration of Aloe vera extract on the number of colonies of Candida albicans was 81.4%. Conclusion: Aloe extract is effective in reducing Candida albicans colonies on the acrylic base of removable orthodontic appliances.