Background: The objectives of this study were to develop a grading system to enable pre-operative prediction of technical difficulty of laparoscopic cholecystectomy using retrospective data and to attempt to validate our scoring system prospectively.Methods: Retrospective analysis was conducted of 100 consecutive patients. Pre-operative variables were collected based on a template devised by the American College of Surgeons. Outcomes were duration of surgery, conversion to open and post-operative complications. Multivariate analysis with subsequent measurement of hazard ratios was used to formulate a weighted grading system. Prospective analysis was performed of 100 consecutive patients who were scored pre-operatively. Outcomes were duration of surgery and length of stay.Results: Retrospective univariate analysis identified four variables associated with an increase in duration of surgery: male gender (p = 0.023), age (p = 0.000), body mass index (BMI) (p = 0.000) and pre-operative endoscopic retrograde cholangiopancreatography (ERCP) (p = 0.001). Prospective analysis revealed weak positive correlations between the scoring system and duration of surgery (0.34) and length of stay (0.40).Conclusion: We have identified four pre-operative variables that predicted a longer duration of surgery. Preliminary results suggest a positive correlation between this scoring system and duration of surgery. An adequately powered prospective multi-centre study is needed to validate our findings. [ABSTRACT FROM AUTHOR]