The ability to make an objective evaluation of a surgeon's operative ability remains an elusive goal. In this study, we used motion analysis as a measure of dexterity in the performance of a simulated operation.Fifteen surgeons performed a total of 45 laboratory-based laparoscopic cholecystectomies on a cadaveric porcine liver model. Subjects were assigned to one of three groups according to their level of experience in human laparoscopic cholecystectomy. Electromagnetic tracking devices were used to analyze the surgeon's hand movements as they performed the procedure. Movement data (time, distance, number of movements, and speed of movement) were then compared.Analysis of variance (ANOVA) movement scores across the three groups showed significantly better performance among the experienced laparoscopic surgeons than the novices. Learning curves across repetitions of procedures were plotted. Novices made more improvement than experts.Motion analysis provides useful data for the assessment of laparoscopic dexterity, and the porcine liver model is a valid simulation of the real procedure.