The long-term survival benefit of treating unresectable hepatocellular carcinoma (HCC) patients with transarterial chemoembolization (TACE) rather than conservative treatment remains controversial. This retrospective case-control study evaluated the survival of patients with unresectable HCC treated with TACE, relative to that of patients who received best supportive care.From January 2002 to December 2010, 522 of 2386 consecutive patients with unresectable HCC were enrolled. Patients were treated with TACE (n=347) or best supportive care (non-TACE; n=175). A survival analysis compared the survival of the 2 groups, as well as only those at Barcelona Clinic Liver Cancer Classification (BCLC)-C and Child-Pugh-B (39 TACE, 61 non-TACE).The median follow-up was 5 months (0.15-106 months).The overall median survival of the TACE group (8.0 months) was significantly longer than that of the non-TACE (2.0 months; P .01). Of the patients at BCLC-C and Child-Pugh-B, the overall median survivals of the TACE and non-TACE patients were 6.0 and 2.0 months, respectively (P .01); and the 1, 2, 3, 5, and 8-year overall survival rates were significantly superior in the TACE group (P .01). For all the patients, the independent predictors of survival were treatment modalities, portal vein tumor thrombosis, alpha-fetoprotein, and BCLC stage. Regarding the TACE patients, contributors to prognosis were portal vein tumor thrombosis, alpha-fetoprotein level, and the number of TACE procedures.TACE for unresectable HCC was associated with longer survival compared with best supportive care, especially for patients at BCLC-C and Child-Pugh-B.