This issue of „Postępy Nauk Medycznych” concerning surgical treatment of obesity comprehensively presents the current state of knowledge on this subject. The papers have been drawn up by specialists dealing with these issues in clinical practice. They present their own experiences in this field and achievements of other authors based on the extensive recent literature. This type of study, including epidemiology and non-invasive treatment of obesity, indications for surgical treatment, surgical techniques and instrumentation necessary for the performance of bariatric surgery as well as results of surgical treatment, complications and revision surgeries, is the first detailed presentation of the problem in Poland appearing in published form. The increase of the number of obese persons and the lack of effective non-invasive treatment are the reasons for the development of surgical techniques effective in permanent weight loss as well as in diseases accompanying obesity; hence the usefulness of familiarizing the broad circle of readers of Postępy Nauk Medycznych with these issues. This is a very important topic for GPs, non-surgical specialists and surgeons. The state of knowledge of the medical environment is unsatisfactory in this field. It is necessary to make the medical community aware what a dangerous pathology for health obesity is, and in particular pathological obesity. WHO´s acknowledgement of obesity in 1998 as the epidemic of the 21^{st century underscores the importance of this problem. The implemented preventive programmes – worldwide, European and domestic – will bring results not until several or several dozen years. The scale of the problem is demonstrated by the fact that the number of obese people in the world is greater than the number of undernourished people.}

These data point to the necessity to develop and implement surgical techniques for the treatment of morbid obesity. Technical progress, with the introduction of new technologies and equipment, has helped bring a significant decrease of surgical injuries. Currently all operations for the surgical treatment of obesity can be performed with the laparoscopic technique, which has significantly decreased surgical injury and the percentage of complications, and has improved the quality of life of patients in the post-operative period. Surgical treatments for obesity have had a definite influence on resolution of diabetes mellitus type 2 even in patients who are not obese. During the Congress of the European Association for Endoscopic Surgery in June 2009 Prof. Gagner presented the current achievements in this field. The importance of the problem is reflected by the numerous congresses and world, continental and domestic conventions devoted to this field.