Objective: This study was to verify if the skin cleanser could help decrease the infection ratio of Demodex Folliculorum in acne patients. Methods: 132 participants with mild to moderate vulgaris acne participated in this monocentric, prospective, double-blind study. Dermatologists grading and Standardized Skin Surface Biopsy were performed in baseline and after using cleanser only 7 d later. Results: There was no significant difference between the 2 times for each type of acne, but the number of Demodex Folliculorum was significantly decreased compared with baseline. There was no relationship between the number of Demodex Folliculorum and the total number of acne lesions. Limitations: Short follow-up time in 7 d. Conclusion: Using the cleanser could decrease the average number of Demodex Folliculorum in only 7 d in mild to moderate acne patients. There is no relationship between Demodex and acne lesions number.