The study was carried out to evaluate the effect of Rhododendron molle (Blume) G. Don. extract on hair growth with mental stress. Six‐week‐old female C57BL/6 mice were divided into six experimental groups(n=8/group); the dimethyl sulfoxide (DMSO) group (NC), the DMSO stress group (NCS), the minoxidil group (PC), the minoxidil stress group (PCS), the Rhododendron molle (Blume) G. Don. extract group (RMD), and RMD stress group (RMDS). Hairs of animals were shaved on the dorsal skin before the study and 200 μl once a day of test samples were topically applied for 3 weeks everyday. We observed morphology, length of hair follicle, and no. of mast cells, stem cell factors (SCF) and substance P in skin tissues. Hair follicle depth of RMD(562.0μm) and RMDS(499.2μm) groups were higher than those of NC, NCS, PC and PCS groups. Mast cell number of RMD group(1.4) was the lowest and that of NCS the highest((16.6)(p<0.001). Also, SCF of follicles in RMD‐treated groups was immunohistochemically stained strongly than any other groups. While substance P expression in RMD group was the lowest compared to other groups. From the findings, topical application of RMD extracts increased hair follicle length, hair growth factors, and decreased mast cell and substance P expression. Therefore, it would be beneficial for preventing hair loss or promoting hair growrh. Further research should be conducted to clarify the mechanism of action related to RMD extracts.Grant Funding Source: supported by Basic Science Research Program through the Natiional Research Foundation of Korea(NRF)