Objective: To investigate the possibility and applicability of the staged operation of laparoscopic sleeve gastrectomy (LSG) and duodeno-ileal omega switch (DIOS) in surgical treatment of morbid obesity. Methods: A female morbidly obese patient with concomitant type 2 diabetes and hyperlipidemia admitted in 2012 underwent staged operation of LSG on 13th April of the same year, and then DIOS on 12th March 2013 after 11-month follow-up. The changes in obesity indexes and other relevant parameters of the patient before and after operation as well as the complications were analyzed. Results: The relevant data of the patient at pre-LSG, pre-DIOS and 2 years after DIOS, indicated the body mass index (47.6, 42.3, and 31.0 kg/m2), body weight (140, 125, and 92 kg), glycosylated hemoglobin (6.3%, 5.7%, and 5.0%), blood triglyceride (2.54, 1.87 and 1.26 g/L) and total cholesterol (2.42, 1.89 and 1.68 g/L) all showed a decreasing pattern, moreover, the patient completely eliminated dependency on glucose lowering drugs at two years after operation. During perioperative and 2-year postoperative period, no short- or long-term complications such as anastomotic leakage, malnutrition, alopecia, dump syndrome or biliary reflux occurred. Conclusion: LSG associated with DIOS owns the features of stepwise bariatric operation, and seems to be promising in clinical practice.