A peak height measurement system (PHMS) is described which detects and measures the peak height of several simultaneous pulses with peaks as narrow as 1 nsec. Jitter in the input pulses produces no error in the measured heights. A detailed description of the peak detector circuit is given, and an experimental setup is presented for determining two‐photon absorption cross‐sections with PHMS. It is expected that this system will see application to numerous experiments which use pulsed lasers.