Pancreatic fat accumulation has been described with various terms including pancreatic lipomatosis, pancre-atic steatosis, fatty replacement, fatty infiltration, fatty pan-creas, lipomatous pseudohypertrophy and nonalcoholic fatty pancreas disease. It has been reported to be associated with type 2 diabetes mellitus, acute pancreatitis, pancreatic cancer and the formation of pancreatic fistula. The real incidence of this condition is still unknown. We report a case of pancreatic steatosis in a non-obese female patient initially diagnosed with a mass in the head of the pancreas. Magnetic resonance imaging (MRI) was carried out to define the characteristics of the pancreatic mass. MRI confirmed the diagnosis of fat pan-creas. Enlarged pancreas is not always a cancer, but pancreatic steatosis is characterized by pancreatic enlargement. MRI could give a definite diagnosis of pancreatic steatosis or cancer.