The treatment of psoriasis requires good compliance, efficacy and low toxicity because of its long-term course and wide distribution. The aim of the study was to compare the efficacy of a once daily application of calcipotriol alone or calcipotriol and a superpotent steroid in a premixed form in patients with psoriasis. The monotherapy group of 32 patients with stable plaque psoriasis received 0.005% calcipotriol alone once daily. The combination group of 29 patients was treated once per day with 0.004% calcipotriol/0.01% clobetasol propionate as a premixed ointment. Eruption score of truncal involvement was evaluated. The combination regimen was more efficacious than the monotherapy as evidenced by (1) more patients with at least 50% reduction in the eruption score after 2 weeks, (2) lower eruption score after 6 weeks and later, and (3) less adverse effects. The combined once-per-day application of 0.004% calcipotriol/0.01% clobetasol propionate as a premixed ointment is a promising regimen for psoriasis.