It is well known that UVB therapy of psoriasis vulgaris is potentiated by the association with topical and oral drugs, while till now there have been very few reports on the association between UVB and calcipotriol. In order to evaluate the efficacy and tolerance of this association, we studied 19 patients with psoriasis vulgaris of mild severity (PASI: 5-10). Each patient was treated with UVB and invited to apply calcipotriol 50 micrograms/g ointment twice a day on one lesion usually on elbows or knees in order to compare it with the opposite side. The evaluation of each lesion was performed before and after 4 weeks of therapy. Our data show that the association between UVB and calcipotriol is significantly more effective than UVB therapy alone: 17 out of 19 patients (89%) showed a greater improvement with UVB plus calcipotriol as compared to UVB alone.