Sequential therapy may improve the efficacy and safety of single treatments for severe psoriasis. We compared sequential Cyclosporin A and narrow-band UVB phototherapy versus narrow-band UVB phototherapy alone. A group of 30 patients with severe psoriasis received 3 mg/kg/day Cyclosporin A for 4 weeks. Afterwards, Cyclosporin A was rapidly tapered and phototherapy begun. An additional 30 patients received phototherapy alone. Treatments were given until psoriasis cleared or until partial improvement was achieved without further amelioration despite another week of treatment. Both treatments were highly effective and well tolerated but sequential therapy was more effective in lesions of UV-shielded body areas; itching disappeared more quickly. The cumulative narrow-band UVB dosages and number of exposures were lower. No difference was seen at follow-up extended up to 9 months. Sequential therapy was well tolerated and allowed for the reduction of narrow-band UVB dosage and exposures, quick relief of itching and improvement of UV-shielded lesions.