Purpose: Obesity is an important component of metabolic syndrome. In this study, we aim to research the effect of laparoscopic sleeve gastrectomy (LSG) on metabolic syndrome. Methods: A total of 164 patients who had undergone LSG between January 2013 and August 2016 were included in the study. Data collected from preoperative examinations and follow-ups until the 12th month postoperation were retrospectively analyzed. Results: A total of 86.6% of patients were female and 13.4% were male. The average age was 36.6 years and average body mass index was 45.5 kg/m(2). Excess weight loss was 48.5% in month 3, 67% in month 6, and 83.7% in month 12. The number of patients diagnosed with metabolic syndrome preoperatively was 118; this number dropped to 29 by the 6th month and to 11 by the 12th month. Conclusions: LSG is a very effective procedure for treating metabolic syndrome, which is considered an important cause of mortality and morbidity.