Although bariatric surgery procedures represent well-established methods for sustained weight loss worldwide, an important number of postoperative complications can be expected in both restrictive and mixed procedures. Gastropleural fistulas (GPF) represent an extremely rare life-threatening complication following bariatric surgery. Defined as a pathological communication between the gastric tract and the pleural cavity, the establishment of an appropriate and timely diagnosis may be quite challenging for physicians. We report on a case of a 33-year-old woman, who underwent a bariatric sleeve procedure, who presented several episodes of pneumonia in different occasions postoperatively with undiagnosed causes. Three years postoperatively the patient was hospitalized for a more detailed investigation and underwent video segmentectomy unsuccessfully. GPF was diagnosed following the observation of nutritional supplement escaping through the chest drain. The patient was initially treated with different endoscopic techniques (argon glow plasma, and endoscopic balloon dilatation) for the closure of the GPF, but despite all attempts, she eventually progressed to total gastrectomy. Bariatric surgery patients suffering from recurrent episodes of pneumonia should raise the alert for the possibility of GPF.