Background: Microneedle treatment is a method that creates transdermal microchannels across the stratum corneum barrier layer of skin. Wound-induced hair follicle regeneration via the Wnt/モ-catenin signaling pathway following wounding in adult mice was demonstrated. No previous study showed a therapeutic effect of microneedle on hair growth by wounding. Objectives: We aimed to investigate the effect of repeated microwound formed by microneedle treatment on hair growth and hair-growth-related genes in a murine model. Methods: A disk-type microneedle roller was applied to each group of mice five times a week for three weeks. First, to identify the optimal length and cycle, microneedles of lengths of 0.15, 0.25, 0.5, and 1 mm and cycles of 3, 6, 10, and 13 cycles were applied. Second, the effect of hair growth and hair-growth-related genes such as Wnt3a, モ-catenin, VEGF, and Wnt10b was observed using optimized microneedle. Outcomes were observedusing visual inspection, real-time polymerase chain reaction, and immunohistochemistry. Results: We found that the optimal length and cycle of microneedle treatment on hair growth was 0.25 mm/10 cycle and 0.5mm/10 cycle. Repeated microneedle stimulation promoted hair growth, and it also induced the enhanced expression of Wnt3a, モ-catenin, VEGF, and Wnt10b. Conclusion: Our study provides evidence that microneedle stimulation can induce hair growth via activation of a wound healing process that includes the Wnt/モ-catenin pathway and VEGF.