A two-compound ointment containing calcipotriol plus betamethasone dipropionate is an effective treatment for psoriasis vulgaris. The same active ingredients have now been combined in a gel formulation. Our objective was to compare the efficacy and safety of once daily treatment of the two-compound gel with the single components in the same gel vehicle and the gel vehicle alone, in patients with psoriasis vulgaris on the trunk and/or limbs. 364 patients received once daily treatment for up to 8 weeks with either the two-compound gel, the single components in the gel vehicle or the gel vehicle alone. The percentage of patients whose disease was clear or very mild and who had at least a two-step improvement in the Investigator's Global Assessment of disease severity at week 8, was significantly higher with calcipotriol plus betamethasone dipropionate (27.2%) than with betamethasone dipropionate (16.9%, p = 0.027), calcipotriol (11.4%, p = 0.006) or gel vehicle (0.0%, p < 0.001). This exploratory study showed that the two-compound gel was safe and more efficacious than its individual ingredients in the treatment of psoriasis vulgaris.