OBJECTIVES: Patients with moderate to severe forms of psoriasis reveal lower quality of life. This QoL deterioration comes together with their productivity loss and disability. Therefore, we calculated indirect costs, from societal perspective, of psoriasis in Czech Republic. METHODS: This calculation was based on 6 months-retrospective self-reported questionnaire. We included 179 patients with psoriasis, aged 18-62 years either at working status, partly-disabled or fully-disabled. For calculation of indirect costs we included costs associated with absenteeism (number of missed workdays) and costs associated with disability pension. We used friction costs approach (FCA) with defined friction period of 6 months (130 workdays). The height of average monthly income in year 2009, €851.3 and height of average monthly partly-disability pension and fully-disability pension €229.44 and €365.61, respectively were used for calculation. Indirect costs were expressed as mean value per one patient with moderate to severe form of psoriasis per one year - 2009. Clinical data (PASI score, BSA index and QoL) were collected by dermatologists. RESULTS: Average patients´ age was 45.34 years (23-62 years), average time from diagnosis was 23.9 years. Mean BSA index and PASI score were 26.78% and 13.32, respectively. Occurrence of psoriatic arthritis was 34.1%. Percentage of fully-disabled and partly-disabled patients was 9.5 and 6.1%, respectively. 18.4% of patients reported incapacity to work with average duration of 28.8 workdays in previous 6 months. Mean costs associated with absenteeism, partly-disability pension and fully-disability pension were €214, €168 and €414, respectively. CONCLUSIONS: By using friction cost approach total mean indirect costs of patients with moderate to severe forms of psoriasis were €796 per patient per year. The height of indirect costs was correlated with PASI score, BSA index and QoL.