Background: Hypovitaminosis D has been recognized as a worldwide epidemic. Since vitamin D exerts significant metabolic activities comprising free fatty acids (FFA) flux regulation from the periphery to the liver, its deficiency may promote fat deposition into the hepatocytes. Objective: To investigate plasma vitamin D levels in non‐alcoholic fatty liver disease patients. Patients and methods: This prospective study was carried out at Al-Hussein Hospital, Faculty of Medicine, Al- Azhar University, from June 2019 till December 2019. The present study included 40 middle aged patients which were divided into 2 equal groups: Patients with NAFLD, and patients with NASH who presented with elevated liver enzymes and newly diagnosed via abdominal Ultrasonography or computed tomography (CT). In addition, 20 apparently healthy subjects with normal weight and normal level of vitamin D were included as control group. Results: There was a high significant positive correlation between serum vit. D3 and age, between serum vit D3 and serum albumin. There was a significant positive correlation between Serum VIT D3 and serum urea. Also, there was a high significant negative correlation between serum VIT D3 and ALT, AST, serum bilirubin, direct and 2hpp blood sugar, BMI and Hip circumference. Conclusion: Lower serum 25(OH)D levels were found in NAFLD patients than in subjects without NAFLD.