PURPOSE: To analyze the effect of various parameters used in PEIT on the short-term results of this procedurefor the treatment of small HCC. MATERIALS AND METHODS: Among 76 lesions in 63 patients with HCCs, 66 werediagnosed by tissue biopsy (n=30) or according to clinical features, tumor marker, and the results of angiographyand other diagnostic imagings (n=36). These patients underwent PEIT between November 1993 and October 1996 ; theindications for PEIT were nodular lesions less than 3cm in size, less than three in number, and unsuitable forsurgical resection or transcatheter arterial chemoembolization therapy. The effect of PEIT was evaluated by twophase spiral CT one month later (64 lesions) or by serial ultrasound for 6 months. We analyzed and graded theshort-term effect of PEIT on HCCs as complete remission (CR), partial remission (PR) or no change/aggravation(NC/AG). We also evaluated the correlation between the short-term results of PEIT and variable parameters such assize of the lesion, frequency of PEI per session, Child classification of the patient, the ratio of amount ofinjected ethanol per volume of the lesion, and (alpha-fetoprotein level before the procedure. RESULTS: Thetherapeutic effect of PEIT was CR in 45 lesions (59.2%), PR in 18(23.7%) and NC/AG in 13(17.1%). The size of thetumor, Child-Pugh class, number of injections per session and ratio of injected volume of ethanol to tumor volumewere factors affecting the therapeutic result (p <0.05). CONCLUSION: Sufficient knowledge of prognostic factorsaffecting the short-term results of PEIT might help improve the effects of therapy in patients ith small HCCs.