The accumulation of chylous fluid in the abdominal cavity is an infrequent, yet alarming, complication in abdominal surgery. Laparoscopic fundoplication has assumed a central role in the surgical treatment of gastroesophageal reflux disease and is significantly altering the balance of therapy toward more common and earlier surgical intervention. We report the case of a 67-year-old woman with gastroesophageal reflux disease and intense esophagitis who underwent a laparoscopic Nissen fundoplication in February 2000. The procedure was performed without apparent complications. Twenty days later, the patient complained of abdominal pain and distension. Ultrasonography showed ascites, whereas endoscopic and radiological exploration of the fundoplication demonstrated no abnormalities. A paracentesis was performed, which showed a milky fluid with high concentrations of triglycerides (1024 ng/dL) and cholesterol (241 ng/dL). The patient was treated successfully with total parenteral nutrition for 3 weeks, followed by a low-fat diet. To our knowledge, this is the third reported case of chylous ascites after a Nissen fundoplication and the second case after laparoscopic fundoplication. The development of chylous ascites seems to be related to the injury of lymphatic vessels, including the thoracic duct, during the retroesophageal window dissection. The careful dissection and judicious use of diathermy is proposed to prevent this rare complication.