INTRODUCTION: Psoriasis is a frequent, chronic, systemic immune-mediated disease mainly affecting the skin and joints. AIM: To assess health related quality of life and cost-of-illness in moderate to severe psoriasis associated with psoriatic arthritis. METHOD: A cross-sectional questionnaire survey was conducted at two academic dermatology clinics in Hungary. RESULTS: Fifty-seven patients (65% males) completed the survey with a mean age of 54.3+/-11.6 years and mean EQ-5D score of 0.48+/-0.4. Mean annual total cost was euro8,977 per patient, of which 71% occurred due to biological therapy and 21% were indirect costs, respectively. Permanent work disability due to psoriasis accounted for euro1,775 (95% of the indirect costs). Per patient costs of subgroups not receiving systemic therapy (21%), traditional systemic therapy (32%), and biological systemic therapy (47%) amounted to the sum of euro1,729, euro1,799, and euro16,983, respectively. CONCLUSIONS: Patients on biological therapy showed significantly better health related quality of life. As for health economics, the efficacy of systemic treatments is appropriate to be assessed together in patients with moderate to severe psoriasis associated with psoriatic arthritis, since actual health gain might exceed that reported in psoriasis or psoriatic arthritis separately. Orv. Hetil., 2014, 155(48), 1913-1921.