Background: In the light of laparoscopic cholecystectomy increasingly applied to all forms of cholecystitis, this study aimed at evaluating the safety of laparoscopic cholecystectomy applied to all cases of acute cholecystitis, and at determining factors associated with the risk of conversion to open cholecystectomy. Methods: The clinical, biochemical, radiologic, and operative data from 124 consecutive cases of acute cholecystitis were analyzed retrospectively to determine the complications and morbidity after operation. The data were analyzed further by univariate and multivariate analysis to identify factors associated with conversion. Results: No major bile duct injury or mortality occurred. Bile leak from the stump of the cystic duct developed in four patients. These were managed successfully by endoscopic biliary stent placement. The mean duration of hospital stay was 3.8 days in the laparoscopic group and 8.2 days in the open group. Of the 124 patients (18.5%), 23 underwent conversion to open cholecystectomy. Univariate analysis identified the following factors as associated with conversion: common duct dilation greater than 7 mm observed on ultrasound, (p < 0.05), pericholecystic collection seen on ultrasound (p < 0.0001), emphysematous cholecystitis (p < 0.01), endoscopic retrograde cholangiopancreatographic evidence of Mirizzi syndrome (p < 0.05), and pericholecystic collection at operation (p < 0.0001). On multivariate analysis, only pericholecystic collection (p < 0.015) and gallbladder wall thickness greater than 5 mm (p < 0.013) were statistically significant. Conclusions: Laparoscopic cholecystectomy for acute cholecystitis can be applied safely to all comers, offering the advantage of a shortened hospital stay. Pericholecystic collection, as observed on ultrasound, is associated with a high risk of conversion to open cholecystectomy.