The technique and indications for colonoscopic polyp-ectomy are reviewed. The results compare very favourably with those of surgical polypectomy and represent a major advance. Three hundred polyps of up to 4.5 cm diameter were removed with the diathermy snare from 169 patients, and a further 107 smaller polyps were destroyed with a new ‘hot-biopsy’ technique. There were no serious complications, but I patient sustained a ‘closed’ perforation, which was managed conservatively, and in 2 others signifcant haemorrhage occurred. Comparison of colonoscopy with the Malmö double contrast enema shows that up to 95 per cent of polyps over 5 mm in diameter can be demonstrated radiologically. High quality X-rays allow limited colonoscopy and justify radiological rather than colonoscopic follow-up. Colonoscopic removal of all polyps saves the patient unnecessary irradiation, since barium enema examination need then be repeated only every 3–5 years.