Human epididymis protein 4 (HE4) was recently approved by the Food and Drug Administration to monitor recurrence or progressive disease in epithelial ovarian cancer in conjunction with CA125. This is the first prospective controlled study in literature evaluating the sensitivity and specificity of HE4 and CA125 in detecting recurrent ovarian cancer. Serum samples were obtained 24 h before surgery from 34 patients with suspicious recurrent ovarian cancer and from 34 patients with benign adnexal pathology, operated from November 2010 to November 2011 at University Campus Bio-Medico of Rome. The CA125 normal value is considered less than 35 U/mL. Two HE4 cut-off are considered: less than 70 pmol/L and less than 150 pmol/L. The specificity analysis was performed using the parametric t test to compare the CA125 series and the Mann-Whitney test for the HE4 series. The level of statistical significance is set at p < 0.05. The CA125 sensitivity and specificity in detecting recurrent ovarian cancer is 35.29 and 58.82 %, respectively. The HE4 sensitivity is 73.53 and 26.47 %, for 70 pmol/L and 150 pmol/L cut-off, respectively. The HE4 specificity is 100 %. Combining CA125 and HE4 at cut-off of 70 pmol/L, the sensitivity to detect recurrent ovarian cancer is 76.47 % with a specificity of 100 %. The combination of CA125 and HE4 at cut-off of 70 pmol/L improves the overall sensitivity and specificity of CA125 alone, suggesting a useful application of HE4 in strategies for surveillance of ovarian cancer recurrence.