Inflammatory pseudotumor of the spleen is an uncommon benign mass-like lesion. It can occur in an accessory spleen, which may be found rarely in the pancreas tail. Here, we report the case of a 51-year-old woman with an inflammatory pseudotumor of the intrapancreatic accessory spleen mimicking a fibrous pancreatic mass with hemosiderin deposition. To the best of our knowledge, this is the first case report including radiological and histopathological findings of this extremely rare condition. In conclusion, inflammatory pseudotumor of an intrapancreatic accessory spleen should be regarded as a differential diagnosis in the case of a fibrotic mass with hemosiderin deposition located in the pancreas tail.