This study aimed to characterize the inhibitory effects and patterns of inhibition of green and white tea extracts on: i) tyrosinases originating from mushrooms and a mouse melanoma cell line and ii) melanogenesis. The inhibitory patterns on mushroom tyrosinases were uncompetitive for green and white tea extracts and competitive for arbutin. For tyrosinases extracted from a mouse melanoma cell line, the inhibitory patterns for green tea extract and arbutin were both mixed; white tea extract exhibited a non-competitive inhibitory pattern. IC₅₀ values of green tea extract, arbutin and white tea extract for mushroom tyrosinase were 144 μg/mL, 71.8 μg/mL, and 123 μg/mL, respectively. The IC₅₀ values of green tea extract, arbutin and white tea extract for mouse tyrosinase were 1.8 mg/mL, 122.7 μg/mL and 2.0 mg/mL, respectively. The cell viability of the B16-F10 cell line when treated with 250 μg/mL or 125 μg/mL of extracts were 38% and 75%, respectively (green tea) and 48% and 88%, respectively (white tea). Neither extract was toxic at concentrations below 63 μg/mL. Arbutin was not toxic at all tested concentrations. At a concentration of 63 μg/mL, intracellular melanin contents of cells treated with green tea extract, arbutin, and white tea extract were 69%, 36%, and 21%, respectively, compared with control.