<p> Methodology : This study was a prospective study of 100 patients including all the age groups presenting with the</p> <div>clinical diagnosis of Right iliac fossa lesions and referred for either USG or CT scan . USG was performed using real</div> <div>time Toshiba Nemio XG machine and CT scan was performed using Siemens Somatom sensation 64 slice multi detector CT machine .</div> <div>Results: It was found that incidence of acute appendicitis is most common. CT scan is a useful test to diagnose acute appendicitis in patients</div> <div>with acute right lower quadrant pain .</div> <div>Its sensitivity and speci􀃶cty are better than USG. Second most common among right iliac fossa lesions is ileo-caecal tuberculosis. Other RIF</div> <div>lesions include appendicular lump, carcinoma caecum, mesenteric adenitis, enterocolitis and lymphoma with their speci􀃶c USG and CT</div> <div>􀃶ndings.</div> <div>Conclusion : Ultrasound is the imaging modality of choice in patients presenting with right iliac fossa pain and right iliac fossa lesion</div> <div>,however CT gives better characterization of the disease.</div>