Annona muricata (Annonaceae) and Petunia nyctaginiflora (Solanaceae) were screened for their activity against Herpes simplex virus-1 (HSV-1) and clinical isolate (obtained from the human keratitis lesion). We have looked at the ability of extract(s) to inhibit the cytopathic effect of HSV-1 on vero cells as indicative of anti-HSV-1 potential. The minimum inhibitory concentration of ethanolic extract of A. muricata and aqueous extract of P. nyctaginiflora was found to be 1 mg/ml.