Laparoscopic colo-rectal surgery has been increasingly accepted and performed in several surgical centres. However, there are still concerns about the intra-operative risks and therefore on the safety of the procedure especially during the learning curve. As a matter of fact, in approximately one third of laparoscopic colo-rectal procedures, an intra-operative complication, mainly bleeding or iatrogenic injuries, may occur. In this paper, according to our experience, we analyse step by step the surgical technique of the laparoscopic left colectomy and evaluate the technical difficulties and complications in order to avoid them.