BACKGROUND AND AIMS: In laparoscopic cholecystectomy, the possibility of converting the procedure to an open surgery always exists. The present study evaluates the factors that can predict the laparoscope cases which may require open surgery. METHODS: A total of 314 patients admitted to Yongdong Sevr,rance Hospital for laparoscopic cholecystectomy between November, 1991 and December, 1995 were divided into two groups; the laparoscopic cholecystectomy group, and the cases that were converted into open surgery. The two groups were compared in age, gender, frequency of symptoms, history of open surgery, accompanying diseases, liver function, accompanying pancreatitis, presence of Murphy's sign, hospitalization course, and the thickness of gallbladder wall on preoperative ultrasonograms. The results were analyzed through univariate analysis (g2-test) and the multivariate test using multiple logistic regression model. RESULTS: In univariate ana)ysis, high frequency of conversion to open surgery was observed in males (p=0.017), in patients admitted through the emergency room (p=0.002), in those with positive Murphys sign it admission (p=0.000), in those with history of open surgery (p=0.039), and in those with gallbladder wall thickness exceeding Smm (p=0.001). No correlations were found related to age, accompanying diseases, liver dysfunction, accompanying pancreatitis, and the frequency of the appearance of symptoms. In the multiple logistic regression model, the same correlations were found with particularlyaignificant correlation with those having gallbladder wall thickness of greater than 5mm on ultrasanograms. CONCLUSIONS: Patients with positive Murphys sign and the gall bladder wall thickness of greater than 5mm must be notified of the possibility of open surgery. It may also be necessary, in cases where the severe inflammation and severe tissue adhesion preclude anatomical delineation, to immediately convert to open surgery in order to minimize complications.