Clinically, patients with pancreatic cancer and focal autoimmune chronic pancreatitis share many features, such as being elderly, painless jaundice, new-onset diabetes mellitus, and weight loss. Hence, it is difficult to differentiate between the two conditions. Nevertheless, it is very important to distinguish between focal autoimmune chronic pancreatitis and pancreatic cancer because they have different treatment modalities and prognoses. We encountered a case of a 72-year-old man who developed painless jaundice. The patient was diagnosed with focal autoimmune chronic pancreatitis instead of pancreatic cancer from the CT, ERCP, MRCP findings accompanying with an increased IgG4 level. The abnormalities in the clinical, laboratory, and radiological findings improved after 2 weeks of oral steroid treatment. After 3 months of oral steroid treatment, his disease showed further improvement. To our knowledge, this is a rare case of focal autoimmune chronic pancreatitis that improved with oral steroid treatment. (Korean J Gastrointest Endosc 2007;34:179183)