Photoradiation therapy (PRT), in which hematoporphyrin derivatives (HpD) are activated by an argon-dye laser, was performed on superficial or subcutaneous tumors in 4 vulvar carcinoma, 1 vaginal carcinoma, 1 invasive cervical carcinoma and 8 carcinoma in situ (CIS) of the uterine cervix. In PRT with intravenous administration of HpD, PRT obtained complete response (CR) in one vaginal carcinoma with follow up to 6 months. Histological examination, 7 days after PRT, revealed swelling and edema of the tumor, showing degenerated cells with pyknotic nuclei or weakly stained, swollen nuclei. In PRT with local injection or local attachment of HpD, performed on 9 cervical carcinoma, PRT obtained CR in 2 CIS and PR in 7 carcinoma. A side effect with PRT was found in a patient who received intravenous administration of HpD. All patients who received PRT with local administration of HpD were free of side effects. PRT could be used as a primary treatment or upon tumor recurrence following conventional modalities such as surgery, chemotherapy and radiation therapy. In carrying out PRT, selection of patients and improvement of photosensitizing agents and laser equipment were most important.