According to the 2015 WHO report on overweight and obesity (1), obesity has doubled worldwide in the last 35 years. An estimated 1.8 billion people are overweight and 600 million of them are obese. Obesity among children is also increasing (42 million overweight or obese children under the age of 5). According to the data of the Health Development Institute (TAI), in 2012, 36% of Estonian men and 26% of women were overweight, obesity was 19% in both groups. In the years 2013-2015, 500-600 bariatric surgeries have been performed in Estonia annually. The demand for the service is high, as shown by the length of the treatment queue (1-1.5 years). Based on established practice, patients are referred for surgery by doctors of several specialties. For the development of bariatric surgery, a uniform treatment standard is needed to increase and harmonize the quality of treatment and increase patient satisfaction with treatment. Elevated BMI is a major risk factor for several non-communicable diseases: cardiovascular diseases, type 2 diabetes, joint diseases and respiratory diseases, etc. Over the years, bariatric surgery has proven to be the most effective method in the treatment of obesity. Studies have shown a reduction in preventable deaths and comorbidities in bariatric surgery patients, which in turn reduces healthcare costs (1, 2) As a result of the implementation of the treatment manual, the pre- and postoperative treatment of bariatric surgery patients will be harmonized and their quality of treatment and life will improve.