© 2020 DSR Publishers ∕ The University of Jordan. All Rights Reserved. 1 Faculty of Medicine, The University of Jordan. 2 Thoracic Surgery Department, Mater Misericordiae University Hospital, Dublin. 3 Jordan University Hospital. * Correspondence should be addressed to: email: Mediastinal Masses: Jordan University Hospital (10 Year Experience) Moaath Alsmady 1 , Mohammad Aladaileh 2 , Ibraheem obaidat 3 , Abdullah Nassar 3 , Mohammad Al Qaisi 3 Abstract Background: Mediastinal masses is one of the common diseases faced in thoracic surgical practice, patterns of histopathological distribution of these masses are similar in many reports in the literature, with verities of differences in patients and tumors characteristics. AIM: To describe the most common clinical presentations and histological diagnosis of our patients that are treated by surgery, and to report the experience in our center in treating such patients with surgery. Methods: By reviewing medical records of all patients diagnosed with mediastinal masses at Jordan University hospital over a period of 10 years; from 2005 to 2015. Data about Patients’ demographic characteristics, preoperative and postoperative diagnosis and perioperative course were collected and analyzed. Results: Over a period of 10 years; 100 patients treated with surgery for mediastinal masses at the thoracic surgery division of Jordan University Hospital. 50 % of patients had postoperative diagnosis of masses with thymic gland in origin and another 50 % diagnosed with other masses that were not thymic in origin. Thymic masses tend to occur in younger patients with an average age of 36 years compared with the non-thymic masses which were found in older patients with an average age of 42 years (p value of 0.04). Benign masses (75% of patients) were more common in the diagnosis compared with malignant ones (25 % of patients). No perioperative mortality was reported in our patients, with morbidity of 12%. Post-operative bleeding, pleural effusion and Deep Vein Thrombosis (DVT) being of the most common morbidity. Keywords: Mass, Jordan, Mediastinal Masses (J Med J 2020; Vol. 54 (1):37-46) Received Accepted April 8, 2019 Oct. 3, 2019 Introduction The Mediastinum is the space located in the central part of the thorax and is surrounded by the two pleurae cavities at each side. The thoracic inlet forms the upper border and the diaphragm represents the lower border 1 . The mediastinum consists of three compartments; the anterior, middle and posterior