Antemortem diagnosis of inferior vena cava (IVC) and cardiac metastasis of hepatocellular carcinoma (HCC) is difficult but important before consideration of curative resection. There are only a few cases of cardiac metastasis of HCC which have been diagnosed antemortem by echocardiography. Accordingly, 18 consecutive patients with HCC who were potential candidates for curative resection were studied by transthoracic (TTE) and transesophageal echocardiography (TEE). One (6%) and two (11%) patients had cardiac and IVC metastasis of HCC, respectively, which was detected by two-dimensional TTE. In contrast, by using TEE, four patients (22%) showed tumor invasion of the IVC, of whom two (11%) had tumor mass extending into the right atrium (RA). There was no significant difference in age, serum level of alpha-fetoprotein, and percentage of right liver lobar involvement between those with and without cardiac metastasis. Patients without cardiac metastasis detected on TTE or TEE had significantly longer mean duration of survival (5.0 +/- 2.1 vs. 2.1 +/- 1.0 months; p < 0.05). In summary, TEE may be more useful than TTE in the detection of cardiac metastasis of HCC, which occurred in 22% of patients whose primary tumor was considered to be surgically resectable in our series. This can be safely performed in patients with HCC and can provide optimal visualization of the IVC and RA. The high prevalence of subclinical cardiac metastasis in HCC mandates the use of TEE in all patients with HCC prior to surgical intervention.