Résumé : Ovarian metastasis as first dissemination site of a lung adenocarcinoma has not been described in the literature. We report the case of a 61-year-old woman who had a pneumectomy for a centrally located lung adenocarcinoma, which was discovered on a routine chest X-Ray. During the follow-up, a Positron Emission Tomography (PET)-Scan showed a hypercaptation in the pelvic region. Abdominal CT-scan confirmed the presence of a mass which was compatible with a primary ovarian tumor. The patient underwent a hysterectomy and bilateral salpingo-oophorectomy. Pathology reported an adenocarcinoma. Immunohistochemical staining revealed cells expression for Thyroid Transcription Factor 1 (TTF-1), cytokeratin 7 (CK-7) and focally cytokeratin 20 (CK-20). Clinical course, pathological and immunohistochemical data concluded to the diagnosis of ovarian metastasis of the lung adenocarcinoma. In conclusion, in the differential diagnosis of an ovarian metastasis, clinicians should not forget the lung as primary site since epidemiologic data of lung cancer in women show progressive incidence. © 2005 Elsevier SAS. Tous droits réservés.