The authors present a case of post endoscopic retrograde cholangio-pancreatography acute pancreatitis complicated by a pancreatico-psoas fistula, as well as reviewing similar previously published cases. The patient had a fluctuating clinical course over 4 months, developing multiple life-threatening complications including portal vein thrombosis, gastrointestinal bleeding, aspiration pneumonia and acute kidney injury on a background of chronic kidney disease. The authors followed the long-held surgical principle of draining sepsis and avoiding surgical intervention. The fistula dried up with conservative management and time also allowed portal venous collateral formation with resolution of his ascites.