We report on a series of 60 patients (31 men and 29 women; mean age: 63 years, range: 37-87 years) submitted to brushing and/or biopsy of the biliary tree through a percutaneous biliary drainage. The tumor involved the biliary bifurcation in 13 cases (21.7%), the biliary duct in 32 cases (53.4%), the right hepatic duct in 1 case (1.6%) and the left hepatic duct in 1 case (1.6%). The metal endoprosthesis was obstructed in 6 cases (10%), while a stenosis of the biliodigestive anastomosis was shown in 7 cases. We used a particular bristle brush and a flexible forceps of the alligator type for cholangioscopic biopsy. Forty-three patients had a malignant stenosis; the diagnosis was confirmed histologically and with clinical follow-up. The comparative adequacy of brushing versus biopsy resulted as follows: 33.3% versus 89.6% sensitivity, 100% specificity for both methods and 59.3% versus 89.6% accuracy. We had 14 versus 3 false negatives and no false positives. Neither brushing nor biopsy brought about any complications. To conclude, biopsy is more accurate and sensitive than brush cytology (91.6% vs 59.3% and 89.6% vs 33.3%, respectively) and therefore it is a safer and faster method to diagnose obstructive jaundice.