Obesity is global health problem leads to many life-threatening illnesses, including cardiovascular disease, diabetes mellitus, and metabolic syndrome. In obesity fats infiltration various organs and the infiltrated fats secrete many cytokines leading to the dysfunction of organs such as the gallbladder. Obesity or over weight is a rising health problems. In recent years there is an increasing number of patients referred for surgical treatment of their obesity, which has raised the problem gallstones disease. The prevalence of cholesterol gallstones is high among obese persons. Weight loss further increases the risk of gallstones. Gallstones are a very common problem especially amongst obese people. This primarily happens when cholesterol levels are very high or when fatty deposits are higher than normal levels. The substance produced in the liver responsible for emulsifying fats in the digestive system is called bile. It is a green liquid that keep the cholesterol in suspended form. However, when the cholesterol reaches very high levels the bile is unable to keep it suspended and it begins to form lumps and stones. These are known as gall stones. Patients with morbid obesity are at a higher risk of developing gallstones after bariatric surgery. The increased occurrence of stones is commonly because of super saturation of bile with cholesterol, due to an increased synthesis by the liver and secretion into bile. Known risk factors for gallstones through weight loss are a relative loss of weight more than 24% of original body weight, a proportion of weight loss more than 1.5 kg per week, a very low-calorie diet with no fat, result in a high serum triglyceride level. Gallstone disease can lead to severe complications and often requires hospitalization and surgery. Ursodeoxycholic acid (UDCA) prevents the formation of gallstones after bariatric surgery. UDCA and high fat weight loss diets may be regarded as a primary gallstones formation prophylaxis during weight loss. This is consistent with the reduced cholesterol super saturation of bile, the physio-chemical requirement for reducing gallstone formation risk. Rapid weight loss is associated with deranged cholesterol metabolism in 2 the form of gallstones. UDCA is a safe prophylactic measure against gallstones formation and should be integrated after bariatric surgery. Ursodeoxycholic acid (Ursobil) reduces cholesterol saturation of bile and gallstone occurrence throughout weight loss. Additional preventive options include a control of weight loss rate, a decrease of the extent of overnight fast, and uptake of a minor quantity of fat in the diet. “For patients with obesity and symptomatic gallstone disease, the best strategy complication-wise is to perform cholecystectomy before undergoing bariatric surgery”.