Background: The purpose of this study was to investigate if Sonazoid-enhanced harmonic ultrasonography (US) could be used to evaluate the responses of hepatocellular carcinomas (HCCs) to treatment with transcatheter arterial chemoembolization (TACE). Patients and Methods: Forty-three HCCs that had been treated by TACE were evaluated by Sonazoid-enhanced harmonic US and dynamic computed tomography (CT) approximately 1 week after their treatment. The detection rates of residual tumor blood supply using the two modalities were compared. Two months after chemoembolization, 16 of the 43 HCCs, which had no additional local treatment, were followed up with dynamic CT. The results of contrast-enhanced harmonic US and dynamic CT 1 week after chemoembolization were analyzed and compared with follow-up dynamic CT results. Results: The detection rates of positive enhancement with Sonazoid-enhanced harmonic US and dynamic CT 1 week after TACE were 25 (58.1%) of 43 lesions and 17 (39.5%) of 43 lesions, respectively. Sonazoid-enhanced harmonic US was significantly more sensitive than dynamic CT in depicting the residual tumor blood supply to HCCs 1 week after TACE (p < 0.01; χ2 test). The Sonazoid-enhanced harmonic US results of the 16 lesions 1 week after chemoembolization were consistent with the follow-up results of dynamic CT 2 months after chemoembolization. Conclusions: Sonazoid-enhanced harmonic US appears to be a highly sensitive and accurate modality for evaluating responses of HCCs shortly after TACE.