The purpose of this study was: (i) to examine the impact of the clinical severity, anatomical location and treatment of psoriasis on patients' quality of life, and (ii) to investigate the effects of perceptions of psoriasis-related stress on patients' physical and mental health and on areas of disability in everyday life. All patients (n = 204) attending a psoriasis specialty clinic were invited to complete a multidimensional quality of life assessment comprising the Psoriasis Disability Index (PDI), the SF-36 Health Survey and the Psoriasis Life Stress Inventory (PLSI). Results (n = 150) indicated that overall clinical severity of psoriasis as assessed by the Psoriasis Area and Severity Index, and duration of psoriasis, were unrelated to impairment in any areas of quality of life. Anatomical location (social visibility) of psoriasis was associated with self-report of poor physical health (P = 0.01), and there was a modest association with patients' mental health (P = 0.04); however, anatomical location of psoriasis was not significantly associated with self-reported disability in everyday life, or stress scores. Patients who were classified as more reactive to the stress associated with psoriasis (78% of the sample) were functioning less well in terms of their mental health (P = 0.001) and also experienced significantly more disability in all areas of everyday life (P = 0.001). Differences in method of treatment for psoriasis did not significantly affect scores on the psoriasis-specific (PDI; PLSI) or generic (SF-36) quality of life measures. A multiple regression analysis demonstrated that stress resulting from anticipating other people's reactions to their psoriasis contributed more to the variance in patients' disability in everyday life than any other medical or health status variable. The results support the importance of assessing the effects of stress in patients' adjustment to their condition and may indicate a role for adjunctive psychological stress management training for a significant number of patients with psoriasis.