50 patients were operated on; 42 women and 8 men at the age of 17 to 57. The weight of the patients was 100 to 184 kg. and the overweight amounted in most cases to 70 to 188%. Long lasting conservative treatment proved to be inefficient. The endocrynological basis of the obesity was excluded. 6 patients were operated upon according to the Salmon-method and 44 according to the Payne-De Wind-method. 3 patients died. 47 patients recovered without complications. For two years after the operation the loss of weight was 28 to 50% compared with the initial weight. Diarrhoe stopped six months after the operation. During this time a decrease in the concentration of potassium and calcium in the blood serum was observed. Judging from the positive changes the decrease of the cholesterol concentration in the blood was observed as well as the general improvement of the patients health. All patients are in good health and have taken up their jobs again.