In the field of surgery the development of operative laparoscopy has been one of the most important steps forward over the past fifteen years. This technique has become the surgical treatment of choice for a number of indications in gynaecology. The advantages of laparoscopy as compared with laparotomy are weil known, and assessment of the risk of complications is essential. A multicentric study was carried out in seven top French centres for laparoscopic gynaecological surgery. This series runs over a period of nine years and covers 29,966 diagnostic and operative laparoscopies. The risk of complications has been assessed according to the complexity of the laparoscopic procedure in question. The means of diagnosis and treatment of the complications have been analysed together with the importance of the surgeon's degree of experience. The mortality rate is 3.33 per hundred thousand laparoscopies. The overall complication rate is 4.64 per thousand laparoscopies (139 cases). The rate of complications requiring laparotomy is 3.20 per thousand (96 cases). The complication rate is significantly correlated with the complexity of the laparoscopic procedure (p = 0.0001). One out of three complications (34.1%; 43 cases) occurred while setting up for laparoscopy, and one out of four complications (28.6%) were not diagnosed during the operation. As new indications for laparoscopic surgery in gynaecology have appeared, there has been a parallel and statistically significant increase in the rate of urological complications (p = 0.001). Increased experience of the surgeons has had three consequences: a statistically significant drop in the number of bowel injuries (p = 0.0003), a drop in the rate of complications requiring laparotomy for those laparoscopic surgical procedures which are weil-defined (p = 0.01) and a change in the way complications are treated, with a significant increase in the proportion of incidents treated by laparoscopy (p = 0.0001). Laparoscopic surgery is a reliable technique. The risk of complications exists whatever the indication for laparoscopy. None of the phases in the operation must be neglected. The risk of accidents being overlooked means that the methods for postoperative follow-up must be adapted, bearing in mind the shorter hospital stay. The part played by the surgeon's experience raises the major problem of practitioner training.