We encountered 4 patients with acute pancreatitis (AP) of various etiologies and coexisting acute cholangitis who underwent endoscopic biliary stenting (EBS) and nasopancreatic drainage (NPD) via endoscopic retrograde cholangiopancreatography (ERCP) during the early phase of AP. ERCP is performed to treat acute cholangitis even in the context of AP. However, in difficult cases, accidental contrast media injection or guidewire insertion into the pancreatic duct can happen during ERCP for the purpose of EBS. It is concerned that cannulation injury and increased pancreatic duct pressure can exacerbate existing AP. Because pancreatic guidewire-associated techniques were required for all of them due to difficult biliary cannulation, we performed a NPD catheter placement using the pancreatic guidewire to decompress the pancreatic duct to prevent further exacerbating AP. Surprisingly, all patients dramatically improved without systemic or local complications. NPD could be performed without any adverse events and did not worsen the course of AP. Early decompression of a pancreatic duct using NPD may rather improve AP that had already developed. Further prospective research is needed to confirm our observations.