By means of videofluoroscopic recordings, chewing, swallowing and speech were monitored in nine patients with congenital and acquired maxillary defects. All of them were rehabilitated with a maxillary obturator prosthesis. The defective region was seldom used for chewing. No leakage between the obturator and surrounding tissue was observed, either for solids or for liquids. All of the prosthetic reconstructions were surprisingly stable during function. In the phonetic analysis, speech production was judged to be restored almost to normal. Videofluoroscopy may be valuable as a complement to other functional diagnostic procedures, and for the evaluation and improvement of rehabilitation with an obturator prosthesis.