Acute necrotic pancreatitis is an emergency of evolution and is often unpredictable because of the potentially life-threatening complications it can cause. We report a unique case of a 56-year-old woman hospitalized for acute necrotic pancreatitis. The evolution of the latter was characterized by the occurrence of two very rare complications, of which the clinical presentations were atypical. The first complication was a gastroduodenal pseudoaneurysm compressing the main biliary tract and causing obstructive jaundice, which evolved well following percutaneous embolization. The second complication was a giant 20 cm pancreatic pseudocyst revealed by obstructive jaundice secondary to biliary compression, which progressed well following surgical treatment.