Several methods were tested for the nondestructive separation of tannins from other plant constituents which might have antitumor activity. A comparison was made of precipitation of tannins by caffeine or lead acetate and chromatography on polyamide. The caffeine procedure was preferred over lead acetate; both tannins and nontannins were effectively separated and the caffeine conveniently removed. Polyamide was an effective tannin remover; nontannins were easily collected but tannins were irreversibly adsorbed. The application of the caffeine procedure to a variety of plants is described.