Disclosed are several embodiments of a battery-less piezo-electric defibrillation system (2) comprising external piezo-electric defibrillator (4) and at least one electrode (5) connected thereto. The system includes a piezo-electric generator (6) connected to direct cardiac access-(5), or indirect subcutaneous electrode assemblies (30). The piezo-electric generator (6) is energized by a spring-driven striker element (8) and produces electrical pulse for defibrillation. The direct cardiac access electrodes (5) engage the heart muscle directly via the intercostal space. Alternatively, indirect subcutaneous electrodes (34a) are positioned under patient's skin.