This prospective study was taken up delineate the profile of mediastinal masses and to study the role of MDCT in detection and characterisation of various mass lesions. The MDCT films of thirty patients presenting with mediastinal masses whose diagnosis was confirmed after surgery and histopathology, were analysed for tumour location, size, number, extent, margins, attenuation, presence of calcifications, enhancement pattern and invasion of adjacent structures. There were 17 males with a mean age of 43.3 years. Two–thirds were in anterior compartment. Benign masses were more common than malignant masses. Thymic   masses, neurogenic   tumor, germ cell tumours and lymphomas were the most common masses. Thymomas were the most common anterior mediastinal masses. Spindle cell sarcoma, pseudocyst and PNET/Ewing sarcoma are rare and likely to be mis–diagnosed. MDCT was accurate in characterising benign and malignant nature of mediastinal mass with the diagnostic accuracy 75.6%.