Cervical intraepithelial neoplasia (CIN) may progress to cervical cancer if left untreated. The loop electrosurgical excision procedure (LEEP) of the transitional zone of the cervix is a standard form of treatment. However, human papillomavirus (HPV)-induced CIN may recur after LEEP. The purpose of this case report is to describe the successful use of 5-aminolevulinic acid photodynamic therapy (ALA-PDT) as an adjunct to LEEP, in preventing the recurrence of CIN.The effectiveness of this combined treatment was evaluated in six women. The diagnosis of HPV-induced CIN was determined using HPV DNA tests and liquid-based cervical cytology. Lesion removal was performed 3 hours after application of ALA using a 635 nm light density of 80 mw/cm.We treated 6 women aged 31 to 62 years who had persistent CIN following LEEP, with ALA-PDT (range, 4 - 7 treatments). Five of the 6 women were HPV negative on retesting 6 - 7 months after ALA-PDT. Most patients showed no signs of recurrence during the follow-up period.Use of ALA-PDT following LEEP may prevent the recurrence of CIN. Monitoring HPV status by means of DNA testing and liquid-based cytology may be used as a standard for clinical diagnosis and treatment. Post-treatment care should be carefully considered because improper post-treatment care might directly lead to relapse.