Identifying patients who are at risk for conversion from laparoscopic (LC) to open cholecystectomy (OC) has proven to be difficult. The purpose of this review was to identify factors that may be predictive of cases which will require conversion to laparotomy for completion of cholecystectomy. We reviewed 581 LCs initiated between July 1990 and August 1993 at a university medical center and recorded reasons for conversion to OC. Statistical analysis was then performed to identify factors predictive of increased risk for conversion. Of the 581 LC initiated, 45 (8%) required OC for completion. Reasons for conversion included technical and mandatory reasons and equipment failure. By multivariate analysis, statistically significant risk factors for conversion included increasing age, acute cholecystitis, a history of previous upper abdominal surgery, and being a patient at the Veterans Affairs Medical Center (VAMC). Factors not increasing risk of conversion included gender and operating surgeon. We conclude that no factor alone can reliably predict unsuccessful LC, but that combinations of increasing age, acute cholecystitis, previous upper abdominal surgery, and VAMC patient result in high conversion rates. Patients with the defined risk factors may be counseled on the increased likelihood of conversion. However, LC can be safely initiated for gallbladder removal with no excess morbidity or mortality should conversion be required.