The noise within an electrocardiogram signal can cause errors that are viewed in the results of different ECG characteristics, in both amplitude and time interval which ultimately lead to a incorrect diagnosis of cardiac disease. In this paper, a new approach of de-noising the electrocardiogram signal is proposed using multiiteration of the moving average filter. The algorithm of the proposed approach includes two main steps: first to estimate the amount of noise presents in the ECG signal, second to remove the noise added. The proposed de-noising approach is validated with ECG records which were collected from the MIT-BIH ECG database with different amounts of additive gauss white noise. The validation results prove the robustness of proposed denoising approach to provide the greatest signal to noise ratio improvement, and to give a reduction of 50% or more in terms of standard metrics used for computing distortion in a noisy signal. Additionally, the filtered signal has a smooth shape in comparison with the adopted de-noising ECG signal techniques.