Hepatocellular carcinoma (HCC) is a disease with a high mortality rate. The surveillance of HCC with ultrasound in hepatitis B patients can improve survival. However, there is no national policy data in Thailand that indicates that hepatitis B patients should receive ultrasound surveillance. This study aims to determine the cost-effectiveness of HCC surveillance, which can be analyzed and displayed in a cost-to-health outcome model. This cost-effectiveness analysis used the decision tree model to assess 1) direct medical cost, 2) direct non-medical cost, and 3) indirect cost. The uncertainty of variables was analyzed. Results were presented as incremental cost-effectiveness ratio (ICER). The ICER of less than 160,000 THB/QALY gained is considered cost-effective according to the threshold of willingness to pay in Thailand. The HCC surveillance group and the non-surveillance group had 0.99 and 0.86 life-year gained (LYG) and 0.68 and 0.58 quality-adjusted life-year gained (QALY gained), respectively. The cost per QALY gained in the HCC surveillance group was 32,518 baht, which is cheaper than 54,589 baht in the non-surveillance group. Besides, the surveillance group had an ICER of 104,392 baht per QALY gained compared with the non-surveillance group. The surveillance for HCC in hepatitis B patients with ultrasound is cost-effective when comparing the willingness to pay in Thailand and 160,000 baht for QALY gained. The study results can be potentially used as information to enhance the policy of public health economics in HCC surveillance of hepatitis B patients.