A gastro-retentive pharmaceutical dosage form comprising a therapeutically effective amount of at least one opioid, at least one form of acetaminophen, optionally an opioid antagonist and at least one pharmaceutically acceptable excipient, which dosage form is retained in the stomach for at least four hours and is suitable for once daily or twice daily administration. Also provided is a method of treating pain by administering the dosage form to a patient in need thereof. The acetaminophen is either in slow release form or in immediate release form or as combination of both.