Obesity, a condition that is characterized by the excessive accumulation and storage of body fat, is one of the most significant and common diseases of today's world and it is measured by a method called body mass index (BMI). Obesity can result in many serious diseases such as, hypertension, diabetes, cardiovascular diseases and hyperlipidemia. Non-alcoholic fatty liver disease is one cause of a fatty liver that occurs when fat is deposited in the liver not due to the excessive alcohol use. Histopathological findings of fatty liver are seen in hepatocytes within the forms of micro-vesicular and macrovesicular steatosis or sometimes housing fat vacuoles. Leptin, one of the most important adipose-derived hormones and among the best-known hormone markers for obesity plays a key role in regulating stable body weight and is synthesized and released by the fat cells in adipose tissue. The aim of this study was to detect the effects of high fat diet induced obesity and leptin on liver by using physical disector and Cavalieri methods. © 2013 OMU.