The size and number of gallbladder polyps are used to differentiate between benign and malignant lesions before surgery and to determine whether surgery is necessary for the lesion. Since 1987, laparoscopic cholecystectomy has been widely used as the management method of choice for gallbladder lesions. The results of a clinicopathologic study of polypoid lesions of the gallbladder, based completely on laparoscopically resected gallbladder tissue, have not yet been evaluated fully. Data from 123 patients with polypoid lesions of the gallbladder treated by laparoscopic cholecystectomy were reviewed retrospectively. The gallbladders were classified into four histologic groups. Clinical features, maximal diameter, and the number of lesions were compared among the groups. The mean age of patients with adenoma and cancer was significantly greater than that of patients with cholesterol polyps and other lesions. More women than men had a neoplasm (adenoma and cancer). Patients in the neoplasm group tended to have a single lesion. The mean maximal diameter of neoplasms was significantly larger than that of lesions in the nonneoplasm group. All seven malignant lesions that were detected measured at least 1.5 cm. Univariate analysis showed that polypoid lesions of the gallbladder with neoplastic lesions correlated significantly with age, sex, size, and number of the lesions. Univariate analysis also showed that malignancy in polypoid lesions of the gallbladder correlated significantly with age, size, and number of the lesions. Multivariate logistic regression analysis showed that the age of the patient and the size of the lesion (> or = 1.0 cm) are two independent factors in predicting neoplastic lesions in polypoid lesions of the gallbladder. The size of the lesion (> or = 1.5 cm) is the only independent factor in predicting malignancy in the polypoid lesions of the gallbladder as shown by multivariate logistic regression analysis. Laparoscopic cholecystectomy is a safe and feasible method for gallbladder polypoid lesions. Neoplastic change in polypoid lesions of the gallbladder should be considered when a patient older than 50 years of age has a polypoid lesion larger than 1.0 cm. Cancer should be suspected when a polypoid lesion of the gallbladder is larger than 1.5 cm, and an aggressive surgical approach is warranted so that early gallbladder cancer can be detected and patients can have an increased chance of cure.