Aqueous extract of Triphala inhibits cancer cell proliferation through perturbation of microtubule assembly dynamics. Triphala interfered with reassembly of the microtubules. Cells treated with Triphala eventually underwent programmed cell death as evidenced by annexin-V staining. Our study shows that the effect of aqueous extract of Triphala is potent enough to interfere with the assembly dynamics of microtubules, and that Triphala can be investigated further for its antitumor potential.