PURPOSE: Obesity is a frequent cause of insulin resistance and poses a major risk for diabetes. The effects of sleeve gastrectomy on diabetes have not elucidated. This report documents that the sleeve gastrectomy provides control for diabetes, prior to significant body weight losses. METHODS: We retrospectively reviewed 14 type 2 diabetic patients who underwent laparoscopic isolated sleeve gastrectomy between May 2003 and October 2004. Fourteen patients had type 2 diabetes treated by oral hypoglycemic agents. Preoperative, 4 weeks and 3 months following surgery, all patients checked weight, body mass index(BMI), waist circumference, hip circumference, blood pressure, HbA1c and fasting glucose. RESULTS: Fourteen patients with a mean preoperative body mass index (BMI) of 39.1+/-4.2 kg/m2 (31.9~47.5 kg/m2) underwent laparoscopic sleeve gastrectomy. Changes in mean BMI were minimal (preop: 39.1+/-4.2 kg/m2, postop (4 week): 35.5+/-3.8 kg/m2), but there are significant decrease in blood fasting glucose (P<0.001), HbA1c (P<0.001), systolic blood pressure (P<0.001), diastolic blood pressure (P=0.009). Ten patient did not require medications after surgery (4 week), the other 4 patient stop the medications after surgery (3 month). CONCLUSION: Further evaluation is needed to analyze effect of sleeve gastrectomy in treating type 2 diabetes mellitus. But just with restrictive procedures as isolated sleeve gastrectomy also can control early type 2 diabetes mellitus in morbidly obese patients.