Abstract Background: The formation of cholesterol gallstones is linked to rapid weight loss. As a result, symptomatic gallstone disease is common in patients with morbid obesity who undergo bariatric surgery. Aim of Study: Assessment of the efficacy of ursodeoxy-cholic acid for the prevention of symptomatic gallstone disease after bariatric surgery. Patients and Methods: During this study, 60 obese patients were enrolled, after consenting each of them and divided into two groups; group A received 250mg of ursodeoxycholic acid (Ursofalk®, 250mg, Hard Capsules, Mina Pharm, Egypt) twice a day (total dosage of 500mg/d) within 3 days after surgery and continuing for 6 months or until gallstone devel-opment and group B received placebo of ursodeoxycholic acid twice a day for 6 months within 3 days after surgery and continuing for 6 months or until gallstone development. Results: Number of cases who developed gall stones were statistically significant lower 3 (10.0%) in study compared with control group 27 (90.0%) with no significant differences between both groups as regard presenting symptoms which indicates that ursodeoxycholic acid is effective in prophylaxis against development of post-operative gall stones. There was no statistically significant relation between excess weight loss level and type of bariatric operation and increasing risk of development of gall stones. Conclusion: Ursodeoxycholic acid is effective in preven-tion of postoperative symptomatic gallstone disease in obese patients undergoing bariatric surgery. There is no relation between excess weight loss level or type of bariatric operation and increasing risk of development of gall stones.