Introduction: Sleeve Gastrectomy (SG) is becoming more popular due to its weight reducing effect and promising anti-diabetic efficacy. However, long term results are still lacking. Methods: The study focuses on anti-diabetic efficacy of SG through retrospective analysis of data for patients who underwent SG in Germany from 2005 to 2011. Anti-diabetic efficacy was assessed at 1, 2 and up to 4 years after surgery. Results: 5400 morbidly obese patients underwent SG. Of these 5400 patients 13.2% (n = 712) were insulin treated (IT) and 21.6% (n = 1165) were non-insulin treated (NIT). Total follow-up was accomplished in 41.24% of patients. Percentage of remission and improvement (RI) at 1 year was 83.8% (80.2% for insulin treated (IT) vs. 85.1% for non-insulin treated (NIT)). RI% at 2 years dropped to 77.6% (76.9% for IT vs. 77.9% for NIT patients). With late follow up (up to 4 years), RI% was 65.9% (58.8% for IT vs. 66.7% for NIT patients). Difference between IT and NIT patients was insignificant. Conclusion: SG shows promising ant-diabetic efficacy at 1 year, 2 years and up to 4 years after surgery. This efficacy gradually drops with prolonged time interval after surgery and seems to be insignificantly higher among NIT vs. IT patients.