A UV spectrophotometric method for the determination of the total phenolic content of both polyflavonoid and hydrolyzable tannins was presented. The method was compared with the standard method used today for the determination of tanning material in tanning extracts for leather manufacture. In narrow concentration ranges correlation between optical density and phenolic concentration was linear. In wider concentration ranges exponential correlations satisfactorily fitted the experimental data. (C) 2003 Wiley Periodicals, Inc.