Abstract : Nowadays, it is well known that metabolic factors play the most prominent role in explaining why many people develop fatty livers. As too much fat is stored in the liver cells due to a reason other than alcohol, it is called; Non-alcoholic fatty liver disease. There is a strong link between non-alcoholic fatty liver disease and obesity, body response to insulin, hypertension, and unhealthy levels of blood lipids. To evaluate the magnitude and clinical profiles, metabolic profiles, and fibrosis severity of patients with lean NAFLD in comparison to overweight or obese NAFLD. The study had been conducted on 100 patients with NAFLD, who attended the Tropical Medicine Department outpatient clinic, Minia University Hospital, Minia, Egypt, during the period from August 2019 to January 2022. The metabolic syndrome tended to be less common in lean NAFLD patients compared to obese NAFLD (66% vs. 92%). However, at least one criterion of metabolic syndrome was seen in majority (89%, 24/27) of lean NAFLD patients. Non-Alcoholic Fatty Liver Disease - Liver Fat Score (NAFLD-LFS) was of highly significant value (p < .003) in comparing between the obese and lean groups. TGA and LDL levels were found to be high in obese patients than lean patients and this reflected the significant statistical value (p <.001) and (p <003) respectively. Elevated serum uric acid level was an independent risk factor for NAFLD with significant (p value <.001). Non-alcoholic fatty liver is a multifactorial faulty metabolic state which isn’t related only to obese, diabetic nor hypertensive patients. Metabolic impairment is the key word to relate between a fatty liver and other affected body systems. In absence of proper liver biopsy Liver Fat Score (NAFLD- LFS) is of great importance with good significant analytical value to detect NAFLD specially if combined with abdominal ultrasound.