This invention relates to a pharmaceutical composition for oral administration comprising a carrier and, as active ingredient, an opioid (.mu. receptor) agonist, such as fentanyl, or a salt thereof, characterized in that the composition is in the form of a fast-dispersing dosage form designed to release the active ingredient rapidly in the oral cavity. A process for preparing such a composition and the use of such a composition as an analgesic, for the treatment of chronic pain and/or breakthrough pain, as an anesthetic premedication, for the induction of anesthesia, as a sedative and/or for the treatment of anxiety are also provided.