The antiviral activity of alcoholic extracts of several species belonging to the Asteraceae, Labiatae, Plantaginaceae, Schizaceae, Umbelliferae, Usneaceae and Verbenaceae families has been studied. The tests were carried out in Vero celís-pseudorabies virus strain RC/79 (herpes suis virus) system. Eight plant extracts (Achyrocline satureioides, Ambrossia tenuifolia, Baccharis articulata, Eupatorium buniifolium, Mynthostachys verticillata, Plantago brasiliensis, Plantago mayor L and Verbascum thapsus) were able to inhibit at least 2 log, the viral infectivity.