The inhibitory activity against herpes simplex virus type 1 (HSV-1) and type 2 (HSV-2) in vitro, at noncytotoxic concentrations of Urera baccifera (L.) Gaudich. extracts have been evaluated. As for the antiviral activity, the maximum non toxic concentration has been established and this concentration has been used in the anti herpes assay, in vitro. Antiviral activity was determined by reduction of the virus titres. U. baccifera extracts showed the maximum percentage of inhibition against HSV-1-ACVr and the order of activity was found to be butanol fraction > ethyl acetate fraction > ethanol extract. However, the same extracts have not shown expressive percentage of viral inhibition against HSV-2-ACVr.. This is the first report showing antiviral activities for U. baccifera extracts.