Aim. The primary aim of the study was to examine long‑term results of the bariatric surgery (Sleeve Gastrectomy SG) in the treatment of morbid obesity. Procedure. Longitudinal study has been conducted in the Military Institute of Medicine in Warsaw. Methods and Material. The method used in the study was the interview questionnaire. Analyzed indicators: BMI (Body Mass Index) and% of EWL (Percentage of Excess Weight Loss). Results. The average weight of the examined patients a year after the surgery was M=91.8; SD=16.37 and M=91.3; SD=13.15 after 2.5 years after the surgery, which, considering the average weight before the surgery 141.2 kg; SD=22.54, means 44.7 kg weight loss; SD=15.48. The difference is statistically significant. T he average BMI of the patients before the surgery was M=47.55; SD=6.82, a year after the surgery – M=31; SD=4.56, and 2.5 years after the surgery – M=30.85; SD=3.46. The average effectiveness r ate of%EWL a year after the surgery was M=61.97%, SD=14.43%; and 2.5 years after the surgery – M=60.78%, SD=12.88. Conclusions. Bariatric surgery is effective in the treatment of morbid obesity and the results are long‑term.