The present work is probably the first report on cancer chemopreventive potential of Triphala, a combination of fruit powder of three different plants namely Terminalia chebula, Terminalia belerica and Emblica officinalis. Triphala is a popular formulation of the Ayurvedic system of medicine. Our findings have shown that Triphala in diet has significantly reduced the benzo(a)pyrene [B(a)P] induced forestomach papillomagenesis in mice. In the short term treatment groups, the tumor incidences were lowered to 77.77% by both doses of Triphala mixed diet. In the case of long-term treatment the tumor incidences were reduced to 66.66% and 62.50% respectively by 2.5% and 5% triphala containing diet. Tumor burden was 7.27 +/- 1.16 in the B(a)P treated control group, whereas it reduced to 3.00 +/- 0.82 (p < 0.005) by 2.5% dose and 2.33 +/- 1.03 (p < 0.001) by 5% dose of Triphala. In long-term studies the tumor burden was reduced to 2.17 +/- 0.75 (p < 0.001) and 2.00 +/- 0.71 (p < 0.001) by 2.5% and 5% diet of Triphala, respectively. It was important to observe that Triphala was more effective in reducing tumor incidences compared to its individual constituents. Triphala also significantly increased the antioxidant status of animals which might have contributed to the chemoprevention. It was inferred that the concomitant use of multiple agents seemed to have a high degree of chemoprevention potential.