Abstract: This invention provides orally disintegrating pharmaceutical tablet formulations comprising per tablet the following ingredients in the following percentages by weight: olanzapine as an active ingredient in an amount from about 2.5% to about 10%; mannitol in an amount from about 75% to about 95%; a disintegrating agent in an amount from about 1.0% to about 10%; and one or more excipient in a total amount of about 0.1% to about 10%. This invention also provides a method of treating a patient in need of treatment with olanzapine which comprises administering to the patient a therapeutically effective dose of the above pharmaceutical tablet formulations. Finally, this invention provides a method of producing the above pharmaceutical tablet formulation which comprises combining the ingredients in the appropriate relative percentages by weight.