Traditionally physicians have assessed the severity of psoriasis on the basis of involved surface area or other physical features. These measures are not highly reliable and do not quantify the extent to which the disease affects the patient. New approaches to health care assessment have been developed, including evaluation of the outcome of medical care. This new direction in health care assessment has been described as the "outcomes movement." This emphasizes the assessment of patients' outcomes with respect to quality of life and functional capacity, rather than traditional techniques that rely on the results of physical or laboratory examinations. New measures to assess treatment effectiveness will almost certainly be used to allocate health care resources. We review the status of measures of psoriasis and the implications of newer methods for assessing disease impact and outcomes of therapy.