Abstract: The importance of routine mobilization of the left flexure within laparoscopic resections of the left colon is discussed controversially. In the opinion, it should be applied as a standard in these surgical operations. The data of the prospective evaluation of all laparoscopic colectomies were evaluated for a period between 1993 and 2005 with 1091 resections of the left colon or rectum with 72 conversions to an open procedure (conversion rate 6.6%) included. The left flexure was mobilized in 79.2% of all operations. There were no significant differences between the groups regarding the duration, loss of blood and other parameters. The anastomotic leakage rate was 2.2% in this study. A number of resection-rectopexies were included in the percentage of interventions without mobilization of the flexure. The mobilization of the left flexure can be applied as a routine part of left colic resections in a teaching hospital with a large number of participating surgeons and procedures. Using a standardized operation technique with subtle preparation and partially extreme positions of the patient during surgery the mobilization is possible without relevant loss of time and without increased complication rate and a remarkably low leakage rate.