The 10 cases of psoriasis were treated with topical application of 0.3% of Vitamin A acid ointment, once daily, without dressing, and were observed at weekly intervals. Histopathological studies were obtained 5 cases out of former 10 psoriasis patients, before and 3 weeks after treatment. Clinical results(table 1)revealed 6 cases of good result, 4 cases of moderate resuIt in efficacy. In generally, the scales and infiltration were more rapidly responded to the treatment than the erythemas. Histopathological findings after treatment (table 2) were revealed, compare with before treatment, reduced or absence of parakeratosis, regenration of granular cell layer, reduced acanthosis, and decreased inflammatory cell infiltration in the upper derms. Side reaetions, as irritation dermatitis, occurred only on the normaI skin especially periollicular regions, which was cured easily by wet dressing with Burow's solution for a few days. Recurrences were occurred in 3 cases of the treated 10 patients, within 10 days after stop of the therapy.