Background/Purpose: Laparoscopic cholecystectomy (LC) is the standard treatment for symptomatic benign gallbladder disease. The identification of factors that reliably predict the need to convert LC to open cholecystectomy (OC) would help with patient education and counseling. Methods: Between January 2000 and December 2009, 4,698 patients underwent cholecystectomy. LC was attempted in 4,434 patients (94.4%) and OC from the start was performed in 264 patients (5.6%). The causes for conversion were evaluated. The change in conversion rate between 2000 and 2004 and between 2005 and 2009 was analyzed. Factors predictive of conversion were identified by univariate and multivariate analysis. Results: Conversion to OC from an initial LC approach was required in 234 patients (5.3%). The main cause for conversion was dense adhesions (54.7%). Independent risk factors in multivariate analysis were male gender (p < 0.001), increased age (p < 0.001), a history of previous upper abdominal surgery (p < 0.001), a WBC count >9 × 10³/μl, and urgently indicated cholecystectomy (p <0.001). The conversion rate decreased significantly from 6.7 to 3.6% over the two time intervals (p < 0.001). Conclusions: Those at highest risk for conversion are elderly male patients with prior abdominal surgery who present emergently with laboratory evidence of biliary inflammation.