Purpose: To evaluate the effectiveness of topical 5-aminolevulinic acid (ALA)-mediated photodynamic therapy (PDT) for the treatment of cutaneous lichen planus (LP). Methods: A total of 17 symptomatic LP lesions in 7 Chinese patients were assessed. ALA cream (10%) was applied topically to LP lesions for 3 h. The lesions were irradiated with a 635 nm diode laser at the dose level of 100 J/cm². The treatment was repeated at two-week intervals. Clinical assessment was conducted before each treatment. Follow-up was performed once a month for up to six months. Results: Lesions showed significant improvement after one to four courses of treatments. Complete response was achieved in 13 lesions (five patients) and partial remission in four lesions (two patients). The complete response rate was 71%. There was no significant side effects except the feeling of pain that most patients could tolerate. Follow-up of five patients who achieved complete response showed no signs of recurrence. Conclusion: Topical ALA PDT is effective in the treatment of cutaneous LP.