Specimens were collected from clinically suspected mucocutaeous herpetic lesions of patients attending The University Hospital, AL-Yarmouk Teaching Hospital and some private clinics. The total number of the specimens vas 37, 30•( 81.1% ) from orofacial lesions and only 7 ( 18.9% ) from genital lesions. HSV positive isolates were obtained from 23 ( 83.3% } orofacial lesions and 2 ( 28.6% ) genital lesions. None of the patients from whom positive isolations were obtained were receiving or had' received ACV, apart from one patient with recurrent genital lesion.HSV isolations were positive for 100% of vesicular lesions, 100% Of pustular lesions, 64.3% of ulcers and 20% of crusted lesions. Three types of cell cultures were used in this study : PRK cells for viral isolation, PCEF for HSV typing and Vero cells for titration of viral infrctivity, antiviral assay and cytotoxicity assay. Identification of isolates as HSV was achieved by an enzyme immunoassay while HSV typing was based on biological criteria. The virus EDso values of ACV for the 25 isolates of HSV-1 ranged between 0.01 and 0.085 mg/L and that for the two tested strains of HSY-2 were 0.042 and 0.087 mg/L. All the isolates were found to be highly susceptible to ACV as compared with other studies. The locally produced compounds (Nj-1, Nj-2, Nj-3 and Nj-5 ), when tested for their anti-HSV activity, showed an ambiguous effect on viral growth with low in vitro effieacy index ( 2.5, 2.7, 9.2 and 2.9 respectively ) as compared with that of ACV ( 1505.8 ) Antiserum to HSV was prepared in rabbits and was intended to be used for direct detection of HSV antigens in virus infected cells in culinical specimens and infected cell cultures. The antiserum showed an antibody titer of 160 by indirect immunofluorescence test and 512 by indirect haemagglutination test. Scanning electron microscopy' has been used for studying morphological changes in Vero cells infected with HSV as compared with non-infected cells with the future intention of studying the morphological changes in drug treated virus infected cells.