In order to ascertain the damaging effects on the glandular parenchyma and excretory system of the major salivary glands of sialography using iodate contrast media in an oily vehicle, experiments have been carried out on a group of dogs. Among other compounds, Lipiodol UF and Urovison were used, the former oil-based and the latter water-based. Histological slides of the injected gland made three and four weeks afterwards showed in one animal only the presence of a periductal infiltrate and an intracanalicular formation of hyaline thrombotic type that was not easy to interpret. Lipiodol UF was employed in this case. Comparing these results with the literature, it is concluded that Lipiodol is an irritant, especially if it passes beyond the salivary excretory tree, but this is not enough to have it banned absolutely. Contraindications are reported and the need for correct technique stressed.