The purpose of the current study was to observe the effects of sandalwood oil (SO) on hair growth status changes asassessed by gross and histological analyses in a C57BL/6 mouse model of alopecia. C57BL/6 mice were randomized intoeither a normal group (N: saline), a positive control group (PC: 3% minoxidil), or an experimental group (E: 3% SO). SO(100 꺤L) was applied topically to the backs of mice once daily for 5 days a week over a 4-week period, and hair growthstatus changes were observed during 16 weeks. Study results revealed that the hair growth effect in the PC and E groupswas significantly greater as compared to the N group. At week 10, mice in the N group showed 13% hair loss as comparedto week 7, while mice in the both the PC and E groups showed 23% hair growth (both p.0.001). Hematoxylin and eosinstains were used for the histological analyses of skin tissues. During 16 weeks, hair follicle (HF) number, HF depth, anddermal thickness in the PC and E groups were significantly increased as compared to the N group. Additionally, thenumbers of mast cells in the PC and E groups at weeks 4 and 16 were significantly decreased as compared to the N group. In conclusion, SO, like 3% minoxidil, promoted hair growth, maintained an anagen phase, and delayed the transition tothe catagen phase in a C57BL/6 mouse model of alopecia.