NISSEN fundoplication is a common procedure for the management of gastroesophageal reflux disease. It can have the side effect of a "gas bloat syndrome", an accumulation of air responsible for functional symptoms and gastric distension. Gastric necrosis due to gastric distension is a rare event, but with a high mortality rate in case of delayed diagnosis. We describe the surgical management of a partial necrosis of the stomach in a 13-year-old boy with mental retardation. Exploratory laparotomy revealed extensive gastric necrosis without perforation. We performed a partial gastrectomy, without removal of the NISSEN, with reinstatement of gastrostomy, drainage and antibiotic therapy. A posterosuperior gastric fistula appeared in following, leading us to perform a feeding jejunostomy. After three months, the patient was able to return home, fed on the jejunostomy. This is the first pediatric case of partial necrosis of the stomach in the aftermath of a NISSEN, managed by partial gastrectomy. In case of suspected gastric necrosis, an emergency laparotomy associated with a digestive resection procedure seems to be the most indicated. Our case proves that even in case of extensive necrosis, a partial gastrectomy more or less associated with a controlled fistulation can be attempted.