Background: Lichen planus (LP) is a common inflammatory dermatosis with unknown etiology, clinically characterized by purple, polygonal, pruritic papules or plaques affecting the flexor aspects of the wrists, arms, legs, and mucous membranes. The treatment was difficult because of the chronic and relapsing feature. Objective: To evaluate the effectiveness of acitretin in the treatment of LP at Vietnam National Hospital of Dermatology and Venereology (NHDV). Material and method: the clinical trial compared pre-post treatment in 30 patients with confirmed diagnosis of LP by skin biopsies in NHDV from 0312013 to 09/2013. Results: After 8 weeks of oral acitretin 25 mg/day, 100 percent of the patients response to treatment. The ultrasound showed that the thickness of LP was the same with normal skin in 20 patients (66.7 percent). The itching disappeared in all patients. The side effects were not serious. Conclusion: The oral acitretin prescription is an effective method in the treatment of cutaneous lichen planus.