We present a case of ovarian splenoma, a form of heterotopic splenic hamartoma consisting of red pulp tissue. The hamartoma was located in ovarian stroma in an otherwise normal ovary. The histology showed interanastomosing vascular channels of splenic sinusoidal red pulp lined by cells that were immunoreactive for antibodies to von Willebrand antigen and CD8, findings consistent with splenic lining cells. The sinuses were lined by cuboidal to flattened cells with ovoid and grooved bland-looking nuclei. Ultrastructurally, the tumor cells showed Weibel-Palade bodies and lysosomes. To our knowledge, this is the first case of splenic tissue arising in an ovary, and it underlines the trend noted in the literature that splenic hamartoma,although a rare entity, can arise in many retroperitoneal organs, including the ovary.