Background Chemical peeling is a dermatologic treatment for skin aging. However, the mechanism by which the chemical peel achieves its results is not clear. We investigated the effects of chemical peeling and the mechanism of wrinkle reduction in photoaged hairless mice skin. Methods After inducing photoaged skin in hairless mice by repetitive ultraviolet-B irradiation applied over 14 weeks, we applied trichloroacetic acid (TCA) 30%, TCA 50%, and phenol on areas of the same size on the backs of the mice. Punch biopsies were obtained 7, 14, 28, and 60 days after the procedure for histologic and immunohistochemical analyses. Results Histologic examination showed an increase in dermal thickness, collagen fibers, and elastic fibers in the dermis of intervention groups compared with control groups. These increases were maintained significantly for 60 days. Conclusions This study demonstrates that chemical peeling reduces wrinkles and regenerates skin by increasing dermal thickness and the amount of collagen and elastic fibers in photoaged skin.