The preliminary phytochemical investigations have revealed the presence of flavonoids, iridoids, phenolic acids, saponins, amino acids, free sugars, and mucilages in the lyophilized infusion obtained from flowers of Verbascum thapsiforme Schrad. (FVI). Antiviral activity of the FVI on Herpes simplex type 1 virus (HSV-1) was studied in vitro by the yield reduction test. Decrease in the virus titer amounted to about 2.5 log at the non-toxic concentrations of FVI. The inhibitory effect of FVI on HSV studied by plaque reduction test in Vero cells showed that 50% inhibition of virus plaques occurred at 190 micrograms/ml. The virucidal effect of FVI on HSV was also shown.