Background: In countries where ERCP costs are low relative to those of metal stents (eg, Korea), initial endoscopic retrograde biliary drainage (ERBD) with a plastic stent is thought to be more economical. Objective: We conducted this study to compare metal and plastic stent-based ERBD in efficacy, complications, and total cost of biliary drainage. Design: Retrospective study. Setting: Tertiary referral center. Patients: A total of 112 patients who had not undergone previous biliary drainage procedures and who underwent ERBD for unresectable malignant biliary obstruction. Interventions: Endoscopic sphincterotomy was performed, and covered or uncovered Wallstents were used in 56 patients and plastic stents in 56 patients. Results: Stent occlusion occurred in 31 patients after a mean of 278 days in the metal stent group and in 39 patients after a mean of 133 days in the plastic stent group (P = .0004). The incidence of and length of hospitalization for cholangitis were significantly lower in the metal stent group. There was no difference in the total number of drainage procedures between the 2 groups. There was no statistical difference in the mean cost of the relief of jaundice between the 2 groups ($1488.77 in the metal stent group vs $1319.26 in the plastic stent group, P = .422). Limitations: Nonrandomized, retrospective study. Conclusion: Even in countries where ERCP costs are lower than those of metal stents, ERBD with metal biliary stents as the first-line treatment may offer better palliation without a significant increased cost in patients with unresectable malignant biliary obstruction.