A wireless ECG detection system with a low-power analog front-end (LPAF) circuit and a Bio-processing ZigBee (BioZigbee) firmware is presented in this paper. The LPAF circuit comprises an ECG signal acquisition board and a lowpass filter to capture and filter the physical ECG signals from the human body. The low-pass filter in the proposed LPAF circuit is fabricated using the 0.18 μm TSMC CMOS process technology. Its aim is to operate under a supply voltage of only 1 V and a total power consumption of 453 nW. The BioZigbee firmware consists of programs that internally control various electronic devices including the analog-to-digital converter (ADC), the ECG compressor, and the ECG coordinator on the transmitter/receiver to convey the captured ECG signals efficiently and correctly. Results show that the LPAF circuit and BioZigbee firmware work together to perform effective and reliable ECG signal acquisition, processing, and communication.