OBJECTIVES:The objectives of our study being categorization of the masses according to the mediastinal compartments, study their CT characteristics and to compare the CT findings with histopathological findings. MATERIALS AND METHODS: Patients who were suspected to have a mediastinal mass either on clinical examination or on the basis of an abnormal chest radiograph. Thorough clinical history and clinical examination of the patients was done before CT examination. The images were studied in mediastinal, lung and bone window settings. Biopsy of the masses was taken wherever possible. RESULTS: Our study included a total of 50 cases, 31males and 19 females. Cough (n=35, 70%) and dyspnoea (n=28, 46%) were the major presenting complaints. Anterior mediastinum (n=15, 39.4%) is the most commonly involved compartment followed by posterior mediastinum (n=12, 31.5%) and middle mediastinum (n=11, 28.9%). Trans compartmental involvement is more commonly seen involving the anterior and middle mediastinum. The majority of the mediastinal masses are well defined (n=36, 72%), with soft tissue (n=34, 68%) attenuation on plain CT, showing heterogeneous enhancement (n=22, 44%) on contrast study. Masses involved the adjacent structures in 48% cases (n=24) and associated lung findings and bony changes were seen in 64% (n=32) and 14% cases (n=7) respectively. CONCLUSION: To conclude, CT is an important modality in the evaluation of mediastinal masses for their exact localization, analyzing their morphology and arriving at a provisional diagnosis for optimal patient management.