In a prospective, blinded study of 109 patients with cholecystolithiasis, oral cholecystography and 99Tcm-EHIDA cholescintigraphy were compared in terms of reliability for demonstrating cystic duct patency: one of the prerequisites for extracorporeal shock wave lithotripsy (ESWL) treatment of cholecystolithiasis. Patients with a positive result on one or both tests were regarded as having cystic duct patency. Patients with negative and uncertain result of both tests or one of each were regarded as having no cystic duct patency. Concordance between the two tests was obtained in 93 of 109 patients. The diagnostic reliability of cholescintigraphy and oral cholecystography were 95 and 86%, respectively (P < 0.05), suggesting a more precise determination of gallbladder filling with scintigraphy.