The aim of the study was to investigate the effects of arsenic trioxide (As2O3) treatment on the expression of ezrin and serum alpha-fetoprotein (AFP) levels in hepatocellular carcinoma (HCC).A total of 24 patients (20 males and 4 females) with resectable HCC were treated with venous injection of As2O3 for 14 days (10 mg/d) before surgery. The ezrin expression and serum AFP levels were assessed before and after treatment, respectively.The serum AFP levels were 325.5 ng/L before treatment and 278.6 ng/L after treatment, with statistical significant difference (Z = -2.360, P < .05). The expression of ezrin was negative, weak positive, and strong positive in 11, 7, and 6 cases, respectively, before As2O3 treatment, and 17, 5, 2 cases respectively after the treatment. The difference between the 2 groups was statistically significant (χ = 5.619, P < .05). Also, the results showed that there was a significant correlation between the high serum AFP level (AFP ≥ 500 ng/L) and high expression of ezrin (χ = 8.080, P < .05).As2O3 treatment can significantly downregulate the expression of ezrin in HCC.