We report a rare case of sarcoidosis with giant splenomegaly and pancytopenia as a result of hypersplenism. A 44-year-old female patient with sarcoidosis admitted to our hospital for examination of the pancytopenia. Neither blood nor bone marrow disorder was diagnosed by bone marrow examination. Her pancytopenia was thought to be due to hypersplenism. Splenectomy was supposed to be performed to avoid splenic rupture; however, it was impossible because of severe thrombocytopenia. Even after the platelet transfusion, the number of platelets did not increase; thus corticosteroid was systemically administered. Subsequently, a splenectomy was performed following the increase of platelets, and her pancytopenia was improved. In pathological examination, granulomatous lesions were observed in the spleen. Splenomegaly is frequently a comorbid disorder with sarcoidosis; however, hypersplenism was rarely reported even in cases of splenomegaly. Splenectomy following the induction therapy using corticosteroid should be considered for cases of sarcoidosis with giant splenomegaly and pancytopenia as a result of hypersplenism.