A hematologic disorder occurred simultaneously with an ovarian cystic teratoma in a young woman. The blood disorder was a severe thrombocytopenia, with no spontaneous remission, or improvement after steroids tapering. To date, this is the second report in literature of immune thrombocytopenia associated with an ovarian teratoma, completely resolving following surgical excision of the ovarian teratoma. This case may suggest a potential peptide secreted by the ovarian teratoma toxic to platelets, and or a genetic predisposition in patients displaying the syndrome. Further research is needed in this area to highlight the mechanism of association.