Polypoid lesions of the gallbladder (PLGs) are often incidentally identified during ultrasonographic examination of abdominal pain. The present study was designed to determine the reliability of ultrasonography (US) in the diagnosis of PLGs. The records of 853 patients who underwent laparoscopic cholecystectomy (LC) for PLGs in Gazi Medical School from January 2000 to January 2004 were reviewed. Data were collected regarding the patients' gender, age, symptoms, serum lipid levels, the size and the number of polyps on US, surgical indications for PLGs and histopathological diagnosis. In all, 56 of 853 patients had PLGs and underwent LC. Right upper quadrant pain (59%) was the most common presenting symptom that led to gallbladder US. Nearly 75% of the lesions were smaller than 10 mm. At histopathologic examination cholesterolosis was found in 17 of 56 (30%) patients, and 12 of 56 (21%) demonstrated only cholelithiasis; 17 (30%) patients had both cholesterolosis and stones. Only 10 (18%) patients had adenomatous polyp and 8 of these polyps were larger than 1 cm. Overall US-based diagnosis of gallbladder polyp was inaccurate in 82%. The sensitivity and specificity of US for polyps <1 cm was 20% and 95.1%, respectively, whereas the sensitivity and specificity of US for polyps >1 cm was 80% and 99.3%, respectively. The accuracy of US in diagnosing PLGs was poor, especially in polyps <1 cm. © 2005 Taylor & Francis Group Ltd.