Statement of Problems: Candida species are the most common fungal pathogen in human’s body. Therefore an accurate and immediate treatment seems to be necessary. Nowadays, alternative treatments, such as probiotics, are considered because of the adverse side effects of chemical medications. Probiotics are alive organisms which can be used for medical purposes and are added to different kinds of diary such as yoghurt. Lactobacill Acidophilus (LA) was detected form human’s recourses many years ago and nowadays can be found in special kinds of milk, yoghurt, juice and food complementories.Purpose: In this study we are to compare the effect of conventional pasteurized and lactobacillus acidophilus- fortified pasteurized yoghurt on Candida Albicans in vitro.Materials and Method: Candida Albicans was isolated from 30 oral candidasis patients, cultured and prepared as standard suspension. Probiotic powder of LA in MRS Media after 24hrs led to 5×109 lactobacillus. LA- fortified yoghurt was prepared via adding lactobacills into 250 ml of pasteurized boiled milk after 8hrs in 37oc.We prepared 3 tubes and added standard suspension of Candida in each of them. Adding sterile yoghourt, conventional pasteurized yoghurt and LA-fortified yoghurt to the tubes respectively, we put them in 35oc incubator for 48 hrs. We added the content of each tube in Sabouraud agar media and incubated in 25oc for 72 hrs and then counted the colonies.Results: There was a significant difference between the mean of colonies in each group during 5 days ( p = 0, df = 4) and also on each day ( p = 0, df = 2).Conclusion: L.A. can inhibit colonization of Candida in vitro. In this study the most of Candida colonies were in the sterile yoghurt and the least of them were in LA fortified yoghurt.