Inflammatory pseudotumor of the spleen (IPTS) is an extremely rare benign condition of uncertain etiology. Preoperative diagnosis of this entity is usually difficult, only the histological study allows the diagnosis to be made. We report an observation of a 35-year-old women patient, hospitalized for left hypochondrium pain with vomiting. Physical examination noted tenderness of the left hypochondrium and splenomegaly, CT scan showed a large tissue mass, measuring 14x15x9.6 cm, probably at the expense of the upper pole of the spleen, containing central calcifications. Exploratory laparotomy revealed a splenic tumor. A splenectomy was performed. IPTS diagnosis was made after histological and immunohistochemical study of the splenectomy specimen.