Background: Primary mediastinal lesions pose a diagnostic and management challenge and the distribution of these lesions vary depending upon the population being studied and the type of the health-care facility. Methods: A prospective, observational study of consecutive patients presenting for the evaluation of widened mediastinum on the chest radiograph was conducted during the period of January 2012 to January 2016. Patients with primary oesophageal, cardiac, pulmonary masses extending into the mediastinum, metastatic disease, infection (tuberculosis, fungal infections) and sarcoidosis were excluded. Results: We studied 89 histopathological proven cases with primary mediastinal lesions; their mean age was 37.5±20.3 years; there were 50 (56.2%) males. There were 52 (58.4%) benign and 37 (41.6%) malignant lesions. In adults, 39/70 (55.7%) of masses were in the anterior, 11.4% (8/70) in the middle, 10% (7/70) in the posterior and 22.9% (16/70) were in multiple compartments of the mediastinum. In children, 36.8% (7/19) of the masses were in the middle, 31.6% (6/19) in anterior, 21.1% (4/19) in multiple compartment and 10.5% (2/19) in the posterior mediastinum. Lymphomas were the most common lesion 34.8% followed by thymic lesions 26.9%. Conclusion: Most of the primary mediastinal lesions could be diagnosed by image guided fiberoptic needle aspiration cytology/core biopsy