The article describes an unusual occurrence of peri-aortic fibrosis with consequent luminal stenosis in descending thoracic aorta in an adult case of Psoriasis. The report also illustrates the role of Multi-detector CT in the diagnosis of thoracic peri-aortic fibrosis. The patient had received cyclosporine on multiple occasions during acute exacerbation of disease. In absence of any concomitant infective-inflammatory system disorder or atherosclerotic process, the cyclosporine is suggested as a putative etiologic agent for peri-aortic fibrosis.