An ECG sampled at a rate of 250 samples/sec or more produces a large amount of redundant data that are difficult to store and transmit. We need a process to represent the signals with clinical acceptable fidelity and with as small a number of code bits as possible. In this paper, an efficient sub-band coding method for encoding ECG waveforms is presented. It is for the first time that this technique is applied on the encoding of ECG waveforms. The simulation results are presented in terms of bit rates and the qualities of the reconstructed waveforms. The results show that a reproduction with an average of signal-to-noise ratio (SNR) 29.97dB can be achieved even at an average bit rate 0.81 bit/sample.