A green tea polyphenol fraction was evaluated for its ability to inhibit tumor initiation by polycydlic aromatic hydrocarbons and tumor promotion by a phorbol ester in the skin of CD-1 mice. Topical application of the green tea polyphenol fraction inhibited benzo[a]pyrene- and 7,12-dimethylbenz[a]- anthracene-induced tumor initiation as well as 12-O-tetra-decanoylpborbol-13-acetate (TPA)-induced tumor promotion. Topical application of the green tea polyphenol fraction also inhibited TPA-induced inflammation, ornithine decarboxylase activity, hyperplasia and hydrogen peroxide formation. Studies with Individual polyphenolic compounds in green tea indicated that topical application of (—)-epigallocatechin gallate, (—)-epigallocatechin and (—)-epicatechin gallate Inhibited TPA-induced inflanunation in mouse epidermis.