Abstract: The aim of this study is to use discrete wavelet transform (DWT) for ECG signal processing, specifically for reduction of ECG baseline wandering. The main reasons for using discrete wavelet transform are the properties of good representation nonstationary signals such as ECG signal and the possibility of dividing the signal into different bands of frequency. This makes possible the detection and the reduction of ECG baseline wandering in low frequency subsignals. For testing presented method, were used two original ECG signal types; ECG signals recorded in our university and ECG signals taken from MIT-BIH arrhythmia database. The method has been compared with traditional methods such FIR and on-line averaging method and more advanced method such as wavelet adaptive filter (WAF) . It was noticed that presented method is [1] superior to WAF in terms of signal quality and ST-segment distortion, because it cuts the drift from each beat basing on the PQ-segment level.