In this paper, the design and test results of a QRS complex detector are presented. The detection algorithm is based on the Discrete Wavelet Transform and implements an adaptive weighting scheme of the selected transform coefficients in the time domain. It was tested against a standard MIT-BIH Arrhythmia Database of ECG signals for which sensitivity (Se) of 99.54% and positive predictivity (+ P) of 99.52% was achieved. The designed QRS complex detector is implemented on TI TMS320C6713 DSP for real-time processing of ECGs.