Introduction: After cessation of smoking, the best way to prevent health-threatening conditions is to treatment of obesity. Also, obesity treatment, cause alleviation or cure of other diseases. Bariatric surgery in selected obese patients is the best option for preventing health-threatening conditions. Despite the health benefits, this method of treatment -just like other surgical proceduresmay be associated with various side effects. Case Presentation: A 55-year-old female with BMI of 46.5 underwent laparoscopic Omega Gastric bypass surgery. She was admitted due to dyspnea and pulmonary embolism 14 days later. In conducted surveys, platelet count was less than 25,000. In multiple assessments, no cause found for the thrombocytopenia. Corticosteroids prescribed for her with the diagnosis of ITP; which fully responded to treatment. Conclusions: Thrombocytopenia is a rare complication of gastric bypass surgery. Managements include rule out of other causes of thrombocytopenia and medical treatment.