The present invention relates to stable pharmaceutical tablet formulation of adefovir dipivoxil. Specifically, the invention relates to a tablet formulation, comprising pharmaceutically effective amount of adefovir dipivoxil crystalline form 1, characterized in that the tablet is prepared by direct compression method and comprises at least 75% of lactose monohydrate, 10% - 15% of starch, disintegrant and magnesium stearate.