Abstract: The invention relates to a solid formulation for the oral administration of olanzapine that comprises a core of anhydrous olanzapine Form I or a pharmaceutically acceptable salt thereof and, optionally, pharmaceutically acceptable excipients, said core being coated with a functional polymer that acts as filmogenic agent. The method for obtaining it comprises: i) providing anhydrous olanzapine Form I or a salt thereof and, optionally, pharmaceutically acceptable excipients in solid form; ii) providing a functional polymer that acts as filmogenic agent; iii) preparing a dispersion of said functional polymer in an aqueous medium,—and applying the dispersion obtained in step iii) onto the solid form of step i).