Background: UVB is responsible for most of the carcinogenic effects of sun exposure. Objective: Aim of this study was to investigate the regulation and intracellular redistribution of p53 protein after UVB irradiation. Methods: Cultured normal human melanocytes and G361 melanoma cells were used for western blotting and confocal microscopic examination for determining expression and distribution of p53. Results: UVB irradiation increased p53 expression in cultured normal human melanocytes and G361 malignant melanoma cells according to increasing doses of UVB. Furthermore, p53 moved from cytosol to nucleus after UVB irradiation. Conclusions: UVB irradiation induced overexpression and redistribution of p53 in cultured normal human melanocytes and G361 malignant melanoma cells. (Ann Dermatol 13 (3) 133-138, 2001).