SUMMARYA prospective study of P.T.C. using the Chiba Needle in the diagnosis of cholestasis was carried out in 276 patients. The visualization of the biliary system by P.T.C. and the pathological diagnoses were confirmed in 253 patients. The accuracy of P.T.C. in the determination of the level and cause of cholestasis was 100.0% and 96.0% respectively. P.T.C, in our opinion, is still the diagnostic modality of choice, especially in surgically difficult patients.