A prospective study of jaundiced (n = 187) and nonjaundiced (n = 33) cholestatic patients was carried out to evaluate the sensitivity of ultrasonography (US), CT, and endoscopic retrograde cholangiopancreatography (ERCP) in the detection of choledochal stone disease. Altogether 83 patients had the final diagnosis of choledocholithiasis. In the jaundiced patients, the sensitivity of US, CT, and ERCP was 22.5%, 23.2%, and 80.6%, respectively. In cases of cholestasis without jaundice, the values were 20%, 37.5%, and 66.7%. In patients in whom all 3 imaging studies were done (n = 64), the differences between US and ERCP and between CT and ERCP were statistically significant (p less than 0.0001). In most false-negative ERCP studies (10/15), the clinical course of the disease strongly suggested a passed choledochal stone. On the basis of this study, we recommend prompt ERCP to be performed if choledochal stone disease is suspected on clinical grounds.