We evaluate the efficacy of PEIT in patients with HCC using duplex color Doppler US. The study included 27 HCC patients admitted to the University Hospital Centre Zagreb, between 1993 and 1997. PEIT was performed for ablation of tumor supplying vessels in HCCs of < 5 cm in diameter, and as a palliative measure for tumor feeding vessel obliteration in larger tumors. The efficacy of PEIT was evaluated with duplex color Doppler US, and controlled by dynamic CT scan (16 patients) or selective angiography of hepatic artery (11 patients). All patients had well vascularized tumors before PEIT, and after therapy 25 of them showed absent or minimal tumor vascularization. Recanalization of the tumor feeding vessel was detected with Doppler US within 9 months after therapy. Study results suggested that duplex color Doppler US should be the method of choice in the evaluation of PEIT as well as in the follow-up of HCC patients after PEIT.