Acute cholecystitis has been previously considered as contraindication for laparoscopic cholecystectomy (LC), but recently, several studies have demonstrated that the laparoscopic approach can also be effective in such cases, although iatrogenic lesions of the biliary tree have been increasingly reported. Aim of this study was to verify the effectiveness of LC in patients presenting with acute cholecystitis on the basis of preoperative and intraoperative findings, postoperative mortality and morbidity, in order to assess those conditions which still can be considered as contraindications for LC. From September 1992 to January 1995, 133 patients have been consecutively admitted and operated for LC. 46 cases (36.5%) had histologically proven acute cholecystitis. Moreover we have compared preoperative date (clinical history, laboratory findings, Rx and ultrasound evaluation) with intraoperative findings to assess a correlation with intraoperative difficult conditions evaluated according to De Manzini score. Our results demonstrate that clinical data significantly correlate with intraoperative difficult situations. Hepatobiliary ultrasound also has shown good correlation between the thickness of gallbladder wall and difficult operations (73.9 sensibility-70.1 specificity). Therefore, in patients with clinically severe acute cholecystitis, and thickened gallbladder demonstrated by ultrasound it is very likely that the surgeon will experience difficult in intraoperative situations. In these conditions laparoscopy may be considered mainly as a diagnostic procedure in order to evaluate the entity of inflammatory changes considering the possibility of an open conversion that must be done before any iatrogenic lesion occur. This policy has allowed us to avoid in our series postoperative complications such as lesions of the biliary tree. In conclusion we believe that LC for acute cholecystitis should be considered as a therapeutical option only for selected cases.