OBJECTIVE To evaluate the role of Laparoscopic Cholecystectomy (LC) in Acute Cholecystitis (AC) and Chronic Cholecystitis (CC) in terms of hospital stay, operation time, reason and rate of conversion and complications. METHODS Quasi experimental. METHODS Shafieeh Hospital, Zanjan University of Medical Sciences, Zanjan, Iran. The study was carried out prospectively between October 2003 and September 2006. METHODS Fifty patients with Acute Cholecystitis (AC) were admitted to the emergency and performed LC in the first 72 hours following admission labelled as Acute Laparoscopic Cholecystectomy (ALC). One hundred and forty-one patients with AC were admitted for chronic LC, labelled as Chronic Laparoscopic Cholecystectomy (CLC). Patients were excluded with bilirubin greater than 3.5 mg/dl, alkaline phosphates greater than 250 (UL), age >90 years, choledocholithiasis and biliary pancreatitis. Data were collected prospectively which included patients' demographics, medical history, presentation, operative and postoperative time. For the comparison of groups, chi-square analysis, the Student 't' test and Mann-Whitney U test were used. P-value less than 0.05 were considered statistically significant. RESULTS The median of hospital stay were 2 and 3 days in CLC and ALC respectively (P=0.0005). The median of post operative stay were 0.83 and 1 day in CLC and ALC respectively (P=0.0005). The mean of operation time were 39.9, 58.8 minutes in CLC and ALC respectively. Conversion occurred in 5 (3.6%) patients in CLC and in 7 (14%) patients in ALC groups. Major complications were observed in 5 patients (3.6%) in CLC and 2 patients (5.1%) in ALC. 63 (46.3%) patients in CLC, 11 (22%) patients in ALC were discharged less than 10 hours after surgery. CONCLUSIONS This study showed that statistical differences exist in hospital stay, operation time, reason and rate of conversion in two groups, but no such difference in major complications. Laparoscopy appears to be safe and good approach for emergency cholecystectomy in patients with acute cholecystitis.