Non-alcoholic fatty liver disease (NAFLD) is a very common condition among obese patients that may lead to the enlargement of the liver, that in turn impairs the access to the gastro-esophageal junction during laparoscopic bariatric surgery. Omega-3 polyunsaturated fatty acids (Ω-3 PUFAs) supplementation has been shown to reduce nutritional hepatic steatosis. The aim of this study was to assess the effects of a 4-week course of oral Ω-3 PUFAs supplementation on the volume of the liver.