Background: Orthodontic treatment requires time so, duration of orthodontic treatment time needs to be shortened in various ways. Flavonoid is an active content of propolis, that might accelerate tissue regeneration. Flavonoid might increase the number of fibroblast at tension side of orthodontic tooth movement. Purpose: The purpose of this study was to examine the effect of propolis extract gel towards the number of fibroblasts at tension side to accelerate orthodontic tooth movement. Materials and Methods: Thirty male Cavia cobayas were divided into three groups. The first group, ( P) was given treatment to make orthodontic tooth movement and propolis extract gel. The second group, K(+) was given treatment and NaCMC gel. The third group, K(-) was served as control. After 14 days, the Cavia cobayas were sacrified. Fibroblast number was examined with light microscope 400 X. Result: Mean and SD in K(-):100 ± 13,2; K(+):80 ± 13,05; (P):176 ± 17,9. The result of ANOVA test showed significant increase in the number of fibroblasts. The LSD test showed significant result in all groups with significance result p ≤ 0,05. Conclusion: Propolis extract can increase fibroblast number to accelerate orthodontic tooth movement. Keywords: Orthodontic tooth movement, propolis extract, Cavia cobaya, fibroblast. Correspondence: Departement of Orthodontics, Faculty of Dentistry, Hang Tuah University, Arif Rahman Hakim 150, Surabaya, Phone 031-594864, Fax 031-5912191, Email: yukira.yaniela@gmail.com