Serum C-reactive protein (sCRP) levels were measured before and after angiography and transcatheter arterial embolization (TAE) in 25 patients (four angiography, 21 TAE for hepatocellular carcinoma) to examine the correlation of sCRP to patients' reaction to TAE and the efficacy of TAE. Four patients without TAE showed little elevation of sCRP. Twenty-one patients with TAE showed a significant increase in sCRP. Peak levels of sCRP in the patients who achieved partial response were higher than those of the no-change group after TAE (p = 0.005). Peak sCRP levels of patients who showed an adverse reaction to TAE were higher than those of patients with no adverse reaction (p = 0.02). Increased sCRP after TAE reflects not only the degree of untoward reaction but also the effectiveness of TAE. Therefore, measurement of sCRP may be a useful means to assess the effect of TAE.