Laparoscopic cholecystectomy can be performed safely in most patients with symptomatic cholelithiasis. Preoperative evaluation should assess the potential problems that affect the performance of laparoscopic cholecystectomy. Hepatobiliary scintigraphy or oral cholecystography can assess the gallbladder function and nonvisualization of gall bladder usually indicates acute or severe chronic cholecystitis. The purpose of this study was to evaluate the role of preoperative hepatobiliary scintigraphy or oral cholecystography in predicting the performance of laparoscopic cholecystectomy. The study group consists of 176 patients who underwent both hepatobiliary scintigraphy with Tc-99m DISIDA and oral cholecystography within one month before laparoscopic cholecystectomy. Nonvisualization of gallbladder was defined as persistent nonvisualization of gall- bladder until 4 hours on hepatobiliary scintigraphy or 12 hours on oral cholecystography. Among 176 patients, gallbladder was not visualized in 38 patients on hepatobiliary scintigraphy and 41 patients on oral cholecystography, Concordance rate between hepatobiliary scintigraphy and oral cholecystography was 89.2%. The conversion rate to open cholocystectomy was significantly higher in patients with nonvisualization of gallbladder than in patients with gallbladder visualization(15.8% vs 2.9% on hepatobiliary scintigraphy, 12.2% vs 3.7% on oral cholecystography: p〈0.01 and p〈0.05 respectively). The operative complication rate was also significantly higher in patients with nonvisualization of gallbladder (13.2% vs 2.9% on hepatobiliary scintigraphy, 14.6% vs 2.2% on. oral cholecystography : p〈0.0l and p〈0.001, respectively). Similarly, operation time was significantly prolonged in patients with nonvisualization of gall bladder (88.8±41.9min vs 62.5±23.6min on hepatobiliary scintigraphy : p〈0.001, 89.4±41.3 min vs 61.8±22.8 min on oral cholecystography : p〈0.001). It is concluded that nonvisualization of gallblader on hepato biliary scintigraphy or oral cholecystography is a valuable preoperative clincal risk factor in predicting increased conversion rate to open cholecystectomy, increased operative complication and prolonged operation time.