Background and Design: A variety of studies have demonstrated that psoriasis can affect psychological, social and physical functions. The purpose of this study was to determine the impact of the sociodemographic and clinical characteristics on Psoriasis Disability Index (PDI), which is a psoriasis-specific health-related quality of life instrument. Materials and Methods: A total of 70 patients with psoriasis were included in this study and sociodemographic features of the patients, psoriasis area severity index scores evaluated by physician and patient (PASI and SAPASI) and the presence of subjective symptoms associated with psoriasis were recorded. In addition, the patients were asked to complete a questionnaire (PDI) consisting of a series of 15 questions related to daily activities,... work/school, personal relationships, leisure and treatment, dealing with the past four weeks. Correlations between PDI and its subscale scores with sociodemographic and clinical features were analyzed. Results: There were statistically significant positive correlations between mean PDI scores and both of mean PASI and SAPASI scores. Activities of leisure and work/school were found to be more effected in men than in women. PDI and daily activities, personal, work/school and/or leisure activities were also detected to be more effected in patients with cosmetic involvement, severe psoriasis, long duration of disease (≥10 years) and young age of onset. In addition, in patients with subjective symptoms, such as pruritus, muscle pain and fatigue, personal relations, daily and work/school activities were found to be negatively affected. Conclusion: In this study, mean PDI scores correlated significantly both with clinical severity and sociodemographic variables. Nevertheless, we assume that addition of questions examining quality of life related to subjective symptoms such as pruritus would be appropriate.