The present invention relates to an improved process for preparing telmisartan from 4-methyl-6-(1-methyl-1H-benzimidazole-2-yl)-2-propyl-1H-benzimidazole and 2-[4-(bromomethyl)phenyl] benzoate by using condensation reaction and hydrolysis reaction wherein the condensation reaction is performed to prepare an intermediate by using mixed solvent of dimethyl sulfoxide and isopropanol as reaction solvent using dimethyl sulfoxide of 0.5~1.5 times and isopropanol of 1.5~4.5 times on the basis of the usage of 4-methyl-6-(1-methyl-1H-benzimidazole-2-yl)-2-prophyl-1H-benzimidazole and the hydrolysis reaction is performed to cause the reaction in mixed solvent of methanol of 7~9 times and purified water of 5~7 times on the basis of the intermediate. The process for preparing telmisartan according to the present invention provides a simple preparing process for mass production and improves a manufacturing yield with high purity by eliminating an additional process for removing an inorganic salt as a byproduct due to a base used in the condensation reaction and the hydrolysis reaction.
