Herpes simplex virus (HSV) is one of the most common viral infections of the human being. Although most of the seropositive persons do not manifest symptoms, infected individuals may present recurrent infections, characterized by cold sores. HSV-1 infection can result in potentially harmful complications in some patients, especially in those with compromised immunity. We report a clinical case of a patient with severe oral HSV-1 infection in the lower lip. The treatment of the lesions with the association of high-intensity (erbium-doped yttrium aluminum garnet, 2.94 mum, 80 mJ/pulse, 2-4 Hz) and low-intensity (indium gallium aluminum phosphide, 660 nm, 3.8 J/cm(2), 10 mW) lasers has not been reported in the literature. During treatment, no systemic or topical medication was used. Pain sensitivity was completely gone after the first irradiation with the low-intensity laser. During the healing process, lesions were traumatized twice, on the days 4 and 7. Even though the lesions were completely healed within 10 days.