INTRODUCTION: Perforation during colonoscopy is a well-known complication. The purpose of our study was to evaluate the incidence of acute surgical intervention due to colonic perforations during endoscopy at our department, and evaluate the rate of incomplete examinations. METHODS: The latest 4000 colonoscopies performed at Hvidovre Hospital were examined for possible complications and success rate. RESULTS: Seventeen percent of the colonoscopies were incomplete, mostly due to anatomical difficulties, incomplete bowel preparation, and pain. Twelve (0.3%) of the 4000 patients were operated on due to perforation which occurred during the examination. The mortality rate in these 12 patients was 17% and the survivors had a median hospital stay of eight days. DISCUSSION: Future strategy should focus on improving the quality of colonoscopy, thereby increasing the success rate and lowering patient discomfort. Furthermore, the new non-invasive modalities virtual colonoscopy (CT or MRI) should be developed further so that they might substitute all the diagnostic colonoscopies.