A new on-chip transient detection circuit for system-level electrostatic discharge (ESD) protection is proposed. By including this new proposed on-chip transient detection circuit, a hardware/firmware solution cooperated with power-on reset circuit has been analyzed to fix the system-level ESD issues. The circuit performance to detect different positive and negative fast electrical transients has been investigated by HSPICE simulator and verified in silicon chip. The experimental results in a 0.13-mum CMOS process have confirmed that the proposed on-chip transient detection circuit can detect fast electrical transients during system-level ESD zapping.