Virtual colonoscopy is a fundamentally new imaging technique, in which volumetric CT or MRI data are processed to virtual endoscopic images of the colon. The main application is early detection of colorectal cancer. To date, no data of studies on screening for colorectal cancer are available. The results of clinical studies show comparable results for endoscopy and virtual colonoscopy for the detection of clinically relevant polyps (> or = 1 cm) and better results of virtual colonoscopy than of conventional barium studies. Whether virtual colonoscopy as a minimally invasive technique will gain a place in screening for colorectal cancer depends on several issues such as costs, effectiveness and acceptance by patients.