Introduction: Psoriasis is a common chronic inflammatory proliferative skin disease that has many complications including fatty liver that lead to liver fibrosis. The aim of the present study is to investigate the association between the Severity of NAFLD and the Severity of psoriasis.Methods: This descriptive study was conducted on 54 patients with psoriasis, ultrasound was performed and the various factors of Non Alchoholic Fatty Liver and Severity of psoriasis measured. The Severity of psoriasis was calculated using the PASI Score. Data collected inserted to spss16 software and chi-square test and fisher exact analysis was performed.Results: Our study showed that the prevalence of Non Alchoholic Fatty Liver was high in patients with psoriasis and also the Severity of the Non Alchoholic Fatty Liver increases by the higher grade of psoriasis.that the percentage of fatty liver in low Severity in grades 1 and 2 was respectively 42.3% and 0%, and the average intensity was 43.8 % and 12.5% and high intensity was 50% and 33.3 respectively. Also, the number of platelets, TG, cholesterol, LDL, AST, ALTwere associated with psoriasis which was increased strongly with increasing amounts of TG, cholesterol, LDL, AST, ALT.Conclusion: Our study showed that a high prevalence of Non Alchoholic Fatty Liver in patients with psoriasis that can be measured by ultrasonography and risk factors such as TG, cholesterol, AST, ALT. Also the Severity of the Non Alchoholic Fatty Liver increases by the higher grade of psoriasis that is due to factors such as proinflammatory cytokines and adipocytokine that Cytokines trigger psoriasis and increase the Severity of the disease and besides raising these factors resulted in an increasing in insulin resistance and fat accumulation.