Paraneoplastic syndromes are a heterogeneous group of clinical and biological manifestations caused by underling neoplasms. They can reveal ovarian teratoma which express neuroendocrine proteins, or contain mature or immature neural tissue inducing an autoimmune response. The etiological investigation is then crucial to early identification of the tumor in order to optimize the prognosis and to limit neurological sequelae. In case of ovarian teratoma, management is essentially based on surgical resection sometimes associated with immunotherapie. We report two new cases of ovarian teratoma revealed by paraneoplastic syndromes in young and menopausal woman.