Obesity, the prevalence of which is increasing day by day, is a serious health problem. Bariatric surgery provides long-term weight loss by reducing the size of the stomach and restricting calorie intake, thus playing an important role in the recovery of comorbid conditions that occur with obesity. Initial surgeries included bypass surgeries, which left most of the jejunum and ileum out of function, surgeries disabling part of the stomach, and horizontalband gastroplasty. However, serious complications, such as diarrhea, electrolyte imbalance, and liver failure were encountered frequently after surgery in those years. The emergence of obesity as an increasing problem and the ability to perform surgeries that had relatively low morbidity and mortality rates, such as vertical band gastroplasty, led to the spread of obesity surgeries. Deterioration in general health conditions because of obesity, comorbidities, the difficulty of surgical technique, and changes in anatomical structures because of surgery are among the factors that affect the incidence of complications after surgery. Complications detected after obesity surgery are discussed in some sources in three periods as Early (first 30 days), Medium (first year), and Late (after one year). In the literature, it is usually reported as Early Period Complications (first 30 days) and Late Period Complications (after 30 days) as classified in this review. Although obesity is a risk factor for all surgical procedures, it makes bariatric surgery patients even more risky. For this reason, it is important to know the complications, which may occur in the preoperative or postoperative period, to avoid morbidity and mortality.This review will be guiding for nurses and other healthcare professionals who care for patients undergoing bariatric surgery regarding its complications.

Anahtar Kelimeler: Bariatric Surgery, Complication, Obesity