The aim of this study was to assess the quality of colonoscopic procedures in our endoscopy unit with the goal of improving performance. Methods - We prospectively audited 500 consecutive colonoscopic procedures and assessed sixty-two process or outcome indicators for each procedure. Results - Most of the measured indicators were within standard limits: cecal intubation rate (92%), inadequate bowel preparations (24%), inappropriate procedures (9.7%), normal procedures (54%), yield for neoplasia (32%), morbidity (0.4%), and overall patient satisfaction (95.8%). Some indicators were outside standard limits suggesting our practices should be modified: endoscopy withdrawal time less than 6 minutes (78%), forceps removal of polyps (31%), resected polyps not recovered for pathological examination (12%), adenomas with villous elements (22%), patients unsatisfied because of time spent waiting for the procedure (19%), patients unsatisfied because of inadequate explanations (10%). There was no standard for a few indicators: patient discomfort (6.9%), diagnostic success (89%), therapeutic success (92%). Three new indicators were proposed: proportion of patients aged < 50 years, number of normal colonoscopic procedures to perform to detect one advanced adenoma or cancer, and proportion of colonoscopic procedures causing discomfort. The diagnostic yield of colonoscopy was dependent on age, gender, indication and appropriateness of indication but not on the prescriber. Conclusion - This audit allowed us to evaluate our endoscopic practices and to detect certain shortcomings and deviations from standards. It enabled us to change some of our practices with the goal of improving the quality of our colonoscopic procedures.