Aqueous formulation of water dispersible polymers of 3,4-alkylenedioxythiophene comprising a dispersion of nano particles of the polymers of 3,4-alkylenedioxythiophene in water. Also a process for the preparation of aqueous formulation of the water dispersible polymers. The process comprises shearing mixing the polymers in water at a pressure of 100 to 5000 atmospheres to form a dispersion of nano particles of the polymers followed by separating the dispersion by filtration