A new high sensitive voltammetric method of ethinyl estradiol determination on carbon black glassy carbon electrode has been successfully developed using differential pulse technique. The electrochemical behavior of ethinyl estradiol oxidation on the carbon black layer has been investigated using cyclic voltammetry. A linear voltammetric response was obtained for analyte in the concentration range from 0.25 . 10(-6) mol L-1 (7.4 . 10(-5) g L-1) to 3.0 . 10(-6) mol L-1 (8.9 . 10(-4) g L-1), with a detection limit of 0.13 . 10(-6) mol L-1 (3.97 . 10(-5) g L-1) for the preconcentration time of 20 s. Repeatability of the method was determined as RSD % for ethinyl estradiol concentration of 0.5 . 10(-6) mol L-1 as 2.5% (n = 5). The proposed method was successfully applied and validated by studying the recovery of ethinyl estradiol in different pharmaceutical products. The proposed ethinyl estradiol determination by using voltammetric method is simple and short. (c) 2017 The Electrochemical Society. All rights reserved.