Background: The aim of this study was to examine the relationship between weight loss and resistin, apelin, chemerin, and visfatin after laparoscopic adjustable gastric banding (LAGB). Methods: The study group consisted of 19 patients who were operated on for morbid obesity (BMI: 48.7 +/- 6.6 kg/m(2)), and 22 healthy, normal-weight (BMI: 22.9 +/- 2.5 kg/m(2)) subjects formed the control group. We obtained blood samples from the study subjects at three different times: before undergoing surgery and at one month and 6 months after surgery. Blood was obtained once from the control group. Results: Significant weight loss was achieved at one and 6 months after surgery. Plasma levels of apelin, resistin, chemerin, and visfatin were higher in morbidly obese patients compared with the control group. Obesity-related peptides decreased one month and 6 months after surgery. Conclusions: Elevated plasma resistin, apelin, chemerin, and visfatin levels in morbidly obese patients are gradually reduced after weight loss. According to these findings, LAGB surgery is found to be an important and efficient means for morbidly obese patients both to lose weight and to develop a better metabolic risk profile in a short time period.