A unique complication of florid xanthogranulomatous cholecystitis with cholecystoduodenal fistula formation is described in a 6 yr old male. The patient, who had a short gut syndrome, had been maintained on lifelong total parenteral nutrition (TPN) following extensive neonatal ischemic bowel necrosis secondary to gastroschisis. Endoscopic duodenal mucosal biopsy demonstrated a granulomatous inflammatory infiltrate surrounding bile casts suggesting the possibility of a fistula between the biliary tract and duodenum. Additional clinical and radiological evidence of a cholecystoduodenal fistula prompted surgical intervention. At laparotomy the gallbladder was firmly bound to the duodenum by dense fibrous adhesions. Histologic examination showed xanthogranulomatous inflammation in association with fragments of bile that were present both within the gallbladder wall and within a fistulous tract in the adjacent connective tissue.