This single arm study will evaluate the efficacy and safety of sequential treatment with Diavobet (betamethasone propionate 0.5mg/g plus calcipotriol hydrate 50 micrograms/g) once daily for 4 weeks followed by Daivonex (calcipotriol hydrate 50 micrograms/g) twice daily for 4 weeks, in the control of signs and symptoms in patients with mild to moderate psoriasis. Only patients showing a >50% response to Daivobet will progress to the Daivonex maintenance phase. The anticipated time on study treatment is <3 months, and the target sample size is 100-500 individuals.