Extramedullary hematopoiesis (EMH) is a rare disorder, defined as the appearance of hematopoietic elementsoutside the bone marrow or peripheral blood. Usually it is diagnosed incidentally and very rarely it presents asa posterior mediastinal mass clinically mimicking with many other benign or malignant mediastinal tumors.Intrathoracic EMH is a rare condition and only very few case reports have been described in patients withchronic myeloproliferative disorders specially myelofibrosis with myeloid metaplasia and spherocytic anemias.The paravertebral area is an uncommon site for EMH, with the possible exception of sporadically reportedintrathoracic manifestations. In this study, a 38-year-old male patient was followed for myeloproliferativedisease. Tumor-like lesions at the bilateral posterior mediastinum were detected in the patient who applied toour clinic due to fall. Excision was planned with video- assisted thoracoscopic surgery to differentiate frommediastinal tumors, but the mass unblock was removed with posterolateral thoracotomy because of theappearance of the lesion and large size. Histopathologic diagnosis was reported as extramedullaryhematopoiesis. Patient was presented because of its rare location.