The antiherpes virus-1 and genotoxic activities of diethyl ether extract from flowering tops of Helichrysum italicum (Compositae) were investigated. The extract showed significant antiviral activity at concentrations ranging from 400 to 100 microg/ml. This activity was not due to cytotoxic effect of the extract since Vero cells exhibited altered morphology or growth characteristics indicative of cytotoxic effects at higher concentration (800 microg/ml). Moreover H. italicum extract showed no DNA-damaging activity at concentrations up to 2000 microg/disk.