This paper presents removal of noise from the ECG signal by using Digital filters designed with FIR and IIR technique. The analysis of ECG signal has great importance in the detection of cardiac abnormalities. The ECG signal is preserve of the electrical performance of heart versus time. ECG signal of a normal heart beat consists of a three parts P wave, QRS complex and T wave. The P wave reflect the activation of the right and left atria. The QRS complex shows depolarization of the activation of right and left ventricles. Results are obtained for the given order of the filter using windowing technique for the FIR filter. The wavelet transform is used to reduce the effect of noise to get refined signal. The power spectral density and average power, before and after filtration using different window techniques and wavelet utilization at 4 and 6 dB are compared. Order of the filter is also different. Filter with the Kaiser window shows the best result.