BACKGROUND Transarterial chemoembolization (TACE) is the mainstay of management for patients with hepatocellular carcinoma who are not suitable for curative treatments. OBJECTIVE To determine factors associated with mortality after the first TACE procedure. METHODS From January 2004 to May 2008, 60 patients underwent TACE as treatment for hepatocellular carcinoma. Clinical and biochemical parameters before TACE, and response after TACE, were evaluated with conventional classifications (WHO, Response Evaluation Criteria in Solid Tumors [RECIST], and European Association for the Study of the Liver [EASL] criteria) and with one-, two- and three-dimensional assessment. RESULTS Overall median survival after the first TACE procedure was 17.1±3.4 months. According to Cox regression analysis, having an alpha-fetoprotein level of greater than 200 ng⁄mL (HR 2.35 [P=0.02]) and a Model for End-stage Liver Disease (MELD) score of greater than 10 (HR 4.19 [P=0.001]) were associated with higher risk of mortality; whereas reduction in tumour size measured in one dimension (HR 0.96 [P=0.005]), two dimensions (HR 0.98 [P=0.004]) and three dimensions (HR 0.98 [P=0.001]) was associated with lower risk of mortality. Moreover, reduction in tumour size by 3% or more assessed in one, two or three dimensions was associated with lower risk of mortality (HR 0.48 [P=0.04]; HR 0.36 [P=0.01]; HR 0.31 [P=0.003], respectively). The three conventional classifications were not useful for predicting mortality (WHO: HR 1.07 [P=0.9]; RECIST: HR 0.94 [P=0.9]; EASL: HR 0.94 [P=0.9]). CONCLUSIONS Having an alpha-fetoprotein level of greater than 200 ng⁄mL and a MELD score of greater than 10 before undergoing TACE was associated with a greater risk of mortality. Conventional classifications of response were not useful for predicting mortality. Reduction in tumour size after the first TACE procedure was associated with better survival, primarily if patients had more than a 3% reduction in tumour size assessed by three-dimensional measurement.