A 39-year-old Japanese man was admitted to our hospital after experiencing recurrent episodes of pancreatitis over the previous 2 years. On the first episode, he had been admitted to our hospital with elevated serum amylase levels and epigastralgia. Abdominal computed tomography (CT) revealed a diffuse, uncircumscribed area with heterogeneous density in the pancreas. No previous history of pancreatitis, gallstones, drinking, or abdominal injury was elicited. Magnetic resonance cholangiopancreatography (MRCP) demonstrated that the Wirsung duct was unconnected to the Santorini's duct. Endoscopic retrograde cholangiopancreatography through the papilla of Vater and accessory papilla revealed an enlarged ventral pancreatic duct, pancreas divisum, and a cystic lesion in the pancreatic body. On the second and third episodes, endoscopic drainage of the pancreatic pseudocysts through the accessory papilla and ultrasonography-guided transmural drainage were unsuccessful. A follow-up CT and MRCP demonstrated that the pancreatic cyst had enlarged to 9 x 8 cm in diameter. A laparoscopy-assisted cystgastrostomy was performed with an intragastric approach. An anastomosis was performed using an endoscopic linear stapler through the small cystotomy and gastrotomy openings on the posterior wall of the stomach. The postoperative clinical course was uneventful. Over 6 months later, the patient remains well and with a good quality of life. A laparoscopy-assisted cystgastrostomy, using an intragastric surgical technique, offers a safe, less-invasive procedure for cyst drainage by the pancreas divisum.