Lozilurea (N' -3-chlorobenzyl-N'-ethylurea, ITA 312) has shown marked anti-ulcer activity. It has shown itself to be active against chemically and neurogenically induced gastric and duodenal lesions in various experimental animal models. It has no major anti-secretory action. The experimental data obtained suggest that the mechanism of action of lozilurea consists in increasing the protective function of the mucus barrier. It increased gastric levels of hexosamines and mucoproteins. In the screening trials carried out in order to detect the side effects of lozilurea, it has shown sedative, antipyretic and vasodilatory actions.