PURPOSE: To evaluate the difference in each procedure time and complication rates related to percutaneous transhepatic biliary drainage(PTBD) via the right and the left hepatic lobe. MATERIALS AND METHODS: We performed PTBD in 120 patients with biliary obstruction below both main hepatic ducts. Of the 120 catheters, 54 were introduced via a left lobe approach and 66 through the right lobe. All procedures were performed under fluoroscopic guidance by the same operator. For each patient, procedure time was recorded prospectively. PTBD related complications were classified as either early(up to 30 days after procedure) or late(after 30 days), and each complication graded as major, or minor according to its intensity. RESULTS: The difference in the mean procedure time(28.8min versus 36.2rain, left versus right approach group) and that in complication rates (37% versus 58%) were statistically significant(p<0.05). Concerning major complications(bile peritonitis, sepsis, massive hemobilia, liver abscess, pyothorax), the percentages related to left and right lobe approach were 1.8% and 10.6%, and concerning minor complications(catheter obstruction or dislodgement, transient hemobilia, persistent fever or pain), the percentages were 36%and 51%respectively. CONCLUSIONS: PTBD via the left lobe approach was superior with short procedure time and low complication rates than the right approach.