Pancreatic pseudocysts arecomplications of acute and chronic pancreatitis. While most pancreatic pseudocysts are asymptomatic and resolve spontaneously. Rarely, it could drain into the adjacent structure being a vessel, gastrointestinal structure, or open abdominal cavity. Rupture pseudocyst may lead to severe hemorrhage or infection. However, few cases of uncomplicated rupture of pseudocysts were reported in the literature. This case is a rare pancreatic pseudocyst ruptured into the duodenum through a fistula and resolved spontaneously without complications.