Two cases of primary herpes simplex virus type 1 (HSV-1) infection with facial skin lesions and one case with recurrent herpetic lesions in the perioral area were treated by acyclovir ointment in combination with oral or intravenous acyclovir. Acyclovir ointment used in this theraphy was composed of acyclovir, paraffin, vaseline, polyethylene glycol, carboxymethyl cellulose, and sodiumpolyacryl acid. It was found that acyclovir therapy was effective for the treatment of these cases and that acyclovir ointment has no side effect, when applied to the skin lesions. Acyclovir ointment may be useful for the treatment of primary HSV-1 infection and severe recurrent HSV-1 infection if combined with systemic administration of acyclovir.