Purpose: A 58 yo non-diabetic female presented with one week of epigastric pain associated with severe nausea and vomiting. She has been continually treated with palliative chemotherapy with capecitabine since 2006 for metastatic breast cancer, but this has been complicated by severe peripheral neuropathy. Physical examination demonstrated preserved bowel sounds but a diffusely tender abdomen without rebound. Laboratory tests revealed elevated lipase 185 U/L (6-51 U/L), negative anti-neuronal antibody panel, and positive anti-parietal cell antibodies. CT exam showed the stomach to be massively dilated down into the pelvis compressing the pancreas and displacing the aorta laterally, while the intestines appeared normal. EGD was significant for a large amount of retained fluid in the stomach, a widely patent pylorus, and decreased gastric and duodenal peristalsis. Solid phase gastric emptying scan showed 38% emptying after 90 min (normal >50%) consistent with gastroparesis (GP). Despite trials of NGT suctioning, proton-pump inhibitors, metoclopramide, domperidone, pyridostigmine, and octreotide, the patient continued to have copious amounts of gastric secretions with neutral pH (before PPI) suctioned via NGT and was unable to eat. After 3 weeks of continuous NGT suction, during surgical placement of PEG and PEJ tubes for palliative decompression of the stomach and nutrition, full thickness gastric wedge biopsy was obtained and demonstrated loss of myenteric ganglion cells, although the density of cells of Cajal was normal. The most likely cause of the massive gastromegaly and GP in this patient was capecitabine induced visceral neuropathy. GP, a debilitating gastric motility disorder, is most commonly associated with diabetes, gastric surgery, and viral gastrointestinal infection or occasionally medications. Rarely paraneoplastic syndrome may present as GP. In some studies patients with GP have been found to have an inflammatory cell infiltration of the myenteric plexus, and loss of ganglion cells or cells of Cajal. Gastric electrical stimulation (GES) has been used to alleviate symptoms in patients with GP and studies in diabetic rats have demonstrated that long pulse GES may induce regeneration of the myenteric plexus. Capecitabine, a pyrimidine analog antineoplastic agent, is metabolized to fluorouracil in the tissues and inhibits DNA synthesis. Among multiple adverse reactions, capecitabine may cause gastrointestinal dysmotility in 5-10% of patients. GP is a common disorder with severe morbidity. As cancer patients' longevity is increased with long-term chemotherapy, physicians should be aware of and vigilant for possible unusual side effects, including GP.