We measured alpha-fetoprotein doubling time (T2AFP) in 51 patients with hepatocellular carcinoma treated by transcatheter arterial embolization (TAE). We also studied vascular invasion and the survival rate, and looked for correlations. For six patients with T2AFP less than or equal to 30 days after TAE, the time until the finding of vascular invasion by ultrasonography and angiography was 8.5 +/- 3.9 months; for seven patients with T2AFP greater than or equal to 31 days after TAE, it was 17.6 +/- 5.2 months (p less than 0.01). Of 45 patients for whom T2AFP was measured after TAE, 9 were in group A with T2AFP greater than or equal to 61 days, 18 were in group B with an intermediate value, and 18 were in group C with T2AFP less than or equal to 30 days. The two-year survival rate after the first TAE was 55.6% in group A, 42.5% in group B, and 6.0% in group C. The longest survival period was 51 months in group A, 30 months in group B, and 28 months (patient still alive) in group C. In the 18 patients for whom T2AFP was measured before and after TAE, the T2AFP was markedly decreased after TAE in 7 (39%). The pattern of change in T2AFP after TAE was not clearly correlated with the decrease in AFP or the T2AFP value before TAE.