In order to determine the usefulness of anthralin in the treatment of psoriasis, we evaluated the effectiveness of topical anthralin therapy in patients with psoriasis vulgaris in our hospital. Seventy patients with plaque-type psoriasis (58 men and 12 women), aged 17-79 years-old (mean; 47.6 years-old), who were treated at the Department of Dermatology, Tokyo Medical and Dental University, between 1992 and 1999, were retrospectively evaluated. Mean psoriasis activity and severity index (PASI) score before therapy was 24.6. Patients were treated with 0.1-2.0% topical anthralin. Responses were determined by clinical examination. The mean PASI score decreased to 8.7 after three months. The most effective anthralin concentration was 0.4-0.5%. The overall response rate was 85.7%, complete remission was obtained in 21.4%, and partial remission in 64.3%. Ten patients (14.3%) were anthralin-resistant. In all patients who entered complete remission, recurrence was noted within six months after stopping anthralin. Minor skin irritation and pigmentation occurred in most of the patients; however, no severe side effects were noted during the treatment. Our study indicated that anthralin is effective for chronic plaque-type psoriasis.