This is an investigator-blinded, bilateral comparison study. A total of up to 12 subjects with mild to moderate plaque psoriasis will be enrolled in this study, so that at least 10 subjects complete the 4 week trial. These 12 subjects will receive the combination therapy of Clobex® Spray and Vectical® Ointment to treat their psoriatic lesions (except those on the scalp, face, groin, axillae or other intertriginous areas). Half of the subjects will first apply the Clobex® Spray followed by the Vectical ointment to lesions on the right side of their bodies, and Vectical® Ointment first followed by Clobex® Spray to the lesions of the left side of their bodies. The other half of the subjects will first apply Clobex® Spray followed by Vectical® Ointment to the lesions of the left side of their bodies, and Vectical® Ointment first followed by Clobex® Spray to the lesions on right side of their bodies. Treatment will be applied twice daily for 4 weeks. One target area on each side of the subject's body will be chosen for target lesion assessment.