Carcinosarcoma of extragenital organs is rare. In this article, a case of primary carcinosarcoma of the spleen, which presented as painful splenomegaly is reported. To the best of our knowledge, this is the second reported case of primary splenic carcinosarcoma in English literature. The pathogenesis of these tumors is incompletely understood. No specific treatment guidelines exist for these aggressive tumors, surgery being the mainstay of treatment. The prognosis remains poor regardless of the adjuvant therapy used.