Introduction: Sumac has been shown to have a positive impact on lipid profile and hepatic function in some studies. The present study aimed to investigate the effect of sumac consumption on metabolic disorder related to non-alcoholic fatty liver disease (NAFLD) in Iran. It can suggest a therapeutic strategy to reduce the complications of this disease.Methods: According to study inclusion and exclusion criteria 80 patients with NAFLD were selected. They were stratified according to sex, and age, and randomly allocated into two groups each comprised of 40 patients. One group received sumac powder (2 g) and another received placebo (dextrin) for 12 weeks. Blood pressure, aspartate aminotransferase (AST), alanine transaminase (ALT), alkaline phosphatase (ALP), gamma-glutamyl transferase (GGT), lipid profile, leptin and steatosis status were assessed at baseline and end of the study.Results: The administration of sumac powder decreased the systolic blood pressure (SBP) (p = 0.02), but diastolic blood pressure (DBP) did not change (p = 0.14). Also, AST, ALT, ALP, total cholesterol, LDL-C and triglyceride (TG) were decreased but HDL-C was increased in the sumac group compared to the placebo group (p < 0.001). We did not find any change in GGT (p = 0.7) and Leptin between two groups (p = 0.48). The status of steatosis was improved in the sumac group compared to placebo (p < 0.001).Conclusion: Our clinical trial study suggests that sumac powder may be a suitable choice for reducing blood pressure, serum liver enzymes and steatosis in individuals with NAFLD. Also, it can improve lipid profile. Additional studies with a longitudinal design are required to confirm our findings.