OBJECTIVES: To quantify the value to patients of reducing the severity and size of plaque psoriasis (PsO) skin lesions. METHODS: Individuals with a self-reported diagnosis of PsO were recruited from a nationally representative household panel.  Individuals completed a web-based choice-format conjoint analysis survey and were asked to choose between hypothetical treatment pairs in a series of choice questions.  Each choice alternative was defined by lesion severity (redness, thickness, and texture), percentage of body surface area (BSA) covered by the lesions, type of treatment (oral agent, subcutaneous injection, or phototherapy), injection discomfort or pain (if type of treatment included injections), risk of serious lung infection, and monthly out-of-pocket cost.  Preference weights were estimated using mixed logit methods.  Conjoint preference weights were used to calculate willingness-to-pay (WTP) for reductions in lesion severity and BSA.RESULTS: A total of 28,200 panel members were invited to participate in the survey.  A total of 18,330 individuals responded to the invitation and 503 qualified to participate.  A total of 419 PsO patients completed the survey; mean age was 54.5 years and 52% were female; 64% of patients self-reported their PsO severity as mild or mild-to-moderate; 12%, 12%, 7% and 3% of patients self-reported their PsO severity as moderate, moderate-to-severe, severe, and very severe, respectively.  Patients were willing to pay up to $486.73 per month to eliminate severe lesions covering 25% BSA on the arms and legs.  Patients were willing to pay $429.78 each month to eliminate severe lesions of 25% BSA on the torso.  Patients were willing to pay $444.80 per month to eliminate moderate lesions covering 4% BSA on the face. CONCLUSIONS: Individuals with PsO are willing to pay more than $400 out-of-pocket per month to reduce lesion severity and percentage of BSA covered by the lesions.