Laparoscopic surgery is one of the most important surgical innovations of the 20th century. Despite the well-known benefits for the patient, such as reduced pain, reduced hospital stay and quicker return to normal physical activities, there are also some drawbacks. Performing laparoscopic surgery requires specific psychomotor skills and extensive training. Furthermore, training solely on patients is considered unethical and therefore no longer acceptable. Besides the specific psychomotor skills required for laparoscopic surgery, its technical equipment has made the surgical environment more complex and has introduced new risks for the patients safety. The first objective of this thesis is the validation of the VR simulator SIMENDO for the training of laparoscopic psychomotor skills, in order to incorporate this simulator effectively into the surgical curriculum. The second objective of this thesis is the determination of the current problems and needs encountered during laparoscopic surgery in the operation room in order to develop methods to improve safety and efficiency. Validation of the SIMENDO VR simulator. The SIMENDO simulator was subjectively evaluated by a group of experienced laparoscopic surgeons and a group of surgical trainees, inexperienced with laparoscopic surgery (face validation). The groups considered the SIMENDO to be a useful simulator for the training of hand-eye coordination skills for laparoscopic surgery. The learning effect of a simple hand-eye coordination task in the SIMENDO with a single instrument was comparable to the learning effect of a similar task in a box trainer (concurrent validation). The parameters of the tasks in the simulator could distinguish groups with different laparoscopic experience levels (construct validation). The learning curve showed that training on the SIMENDO is useful and valid for subjects with limited or no laparoscopic experience. Training laparoscopic skills on a simulator distributed over several days seems better than training on just one day. Criterion-based training was successfully incorporated in the surgical curriculum. Laparoscopic knot-tying skills acquired on the simulator were shown to be transferable to the knot-tying performance on an animal model. In a randomised controlled trial, subjects that were trained on the VR simulator with the knot-tie module were 30% faster and made 33% fewer errors (transfer or predictive validity) in a laparoscopic animal model, as compared to the control group. Furthermore, a national on-line competition with a reward for the best performance was initiated. The use of competition elements on the simulator may enhance the motivation of surgical trainees to train voluntary. Current problems and needs during laparoscopic surgery in the operating room Analysis of 30 laparoscopic cholecystectomies showed that the incidence of problems with the technical equipment was strikingly high (49 incidents in 30 procedures, only four procedures without technical problems). These problems could be prevented by improvement and standardisation of equipment, in combination with the incorporation of a checklist before the start of the procedure. A structured checklist was developed to prevent incidents with laparoscopic equipment. In the group with the checklist the number of equipment problems decreased with more than 50% compared to the procedures studied previously without the checklist. To gain insight into the communication content during surgical training in the operation room, a classification method was developed. The application revealed that communication was mainly focussed on explaining of the operation method (27%), explaining the anatomy (19%), and learning the positioning of the instrument and how to interact with the tissue (25%). The results of the study may be used to specify training needs and to evaluate different training methods.