After 10 years of prospective study of a cohort of 1,380 patients with psoriasis enrolled in the Photochemotherapy (PUVA) Follow-up Study, our data show that the incidence of death and causes of death were comparable to those expected in the general population. We noted no increase in cardiovascular mortality, but observed that cirrhosis caused more deaths among our cohort than in the general population (Standard Mortality Ratio: 4.7, P less than 0.05). The overall incidence of non-cutaneous cancer was slightly but not significantly elevated in our population (Standard Mortality Ratio = 1.2, P greater than 0.05). In an analysis of individual sites, we observed significant increases in the incidence of colonic cancer and primary neoplasms of the central nervous system. We found no significant increase in the incidence of lymphoma, leukemia, or malignant melanoma within our cohort. Because of the possible long latency time and the low incidence of these malignancies only continued follow-up of this cohort can assure us that PUVA therapy does not substantially alter the risk for the development of these conditions.