The influence of nasal obstruction on the development of the anterior skull base, of the tympanic bulla, and of the Eustachian tube was investigated in three groups of 20 albino Wistar rats in which one (group B) or both nostrils (group C) had been experimentally obstructed by means of synthetic resin mixed with radiopaque material. After two months, a cephalometric investigation demonstrated that the angle formed by the median line passing through the superior interincisive point and the most posterior median point of the occipital bone and by the line connecting the tympanic bulla and the superior interincisive point was significantly increased when the homolateral nostril had been obstructed if compared to controls (group A). On the basis of these preliminary cephalometric observations we suggest that nasal obstruction is able to determine anatomical changes of the superior maxilla, the skull base, and the jaw, with abnormal skeletal growth and consequent possible Eustachian tube dysfunction.