BackgroundTransarterial chemoembolization (TACE) is the standard treatment for intermediate‐stage hepatocellular carcinoma (HCC). Given the lack of specific recommendations for conventional TACE (cTACE) and drug‐eluting bead TACE (DEB‐TACE) in patients having unresectable HCC with tumor infiltrating the common hepatic duct or the first‐order branch of the bile ducts (B1‐type bile duct invasion; B1‐BDI) after biliary drainage, we retrospectively compared the safety and efficacy of DEB‐TACE with cTACE in this patient population.Materials and MethodsUsing data from five tertiary medical centers (January 2017–December 2021), we compared complications, overall survival (OS), time to progression (TTP), and tumor response rate between patients having unresectable HCC with B1‐BDI who underwent DEB‐TACE or cTACE after successful biliary drainage. X‐tile software calculated the pre‐TACE total bilirubin (TBil) cutoff value, indicating optimal timing for sequential TACE after drainage. Propensity score matching (PSM) was performed.ResultsThe study included 108 patients with unresectable HCC (B1‐BDI) who underwent DEB‐TACE and 114 who received cTACE as initial treatment. After PSM (n = 53 for each group), the DEB‐TACE group had a longer TTP (8.9 vs. 6.7 months, p = 0.038) and higher objective response rate (64.2% vs. 39.6%, p = 0.011) than did the cTACE group, although OS was comparable (16.7 vs. 15.3 months, p = 0.115). The DEB‐TACE group exhibited fewer post‐procedural increments in the mean albumin‐bilirubin score, TBil, and alanine aminotransferase (ALT), along with a significantly lower incidence of serious adverse events within 30 days (hepatic failure, ALT increase, and TBil increase) than the cTACE group (all p < 0.05). The pre‐TACE TBil cutoff value was 99 μmol/L; patients with higher values (>99 μmol/L) had poorer OS in both groups (p < 0.05).ConclusionDEB‐TACE is safe and effective after successful biliary drainage in unresectable HCC with B1‐BDI, potentially better than cTACE in terms of liver toxicity, TTP, and ORR. Lowering TBil below 99 μmol/L through successful drainage may create ideal conditions for sequential TACE.