A total of forty-four jaundiced patients were studied by one or both diagnostic modalities (Gray Scale Ultrasonography or Transhepatic Cholangiography--THC--). The thin needle transhepatic cholangiography permitted in vivo correlation of the ultrasonographic findings. Patients with obstruction were confirmed by surgery. Many of the non-obstructive cases underwent liver biopsy. The accuracy of Gray Scale Ultrasonography in differentiation of surgical from medical jaundice dependent on the serum bilirubin level at the time of the examination. For serum bilirubin levels of seven or more milligrams percent, the accuracy was almost one hundred percent. For serum bibiribuin levels of less than seven milligrams percent, the accuracy was approximately eighty-three percent. THC using the thin needle is the ultimate diagnostic procedure and complements the ultrasound information, especially in cases with minimal to moderate icterus. A proposed flow chart for evaluation of the jaundiced patient is presented. The ability to determine the presence of obstruction by demonstrating dilated bile ducts at different levels of serum bilirubin with Gray Scale Ultrasonography was evaluated. Percutaneous TCH using the thin needle (Chiba Needle) made possible the in-vivo correlation of many of the ultrasound findings, as well as the demonstration of surgical jaundice in patients with normal sized bile ducts.