This paper describes design and operation of the flashlamp test system, used to evaluate the primary laser flashlamps on the National Ignition Facility (NIF) at the Lawrence Livermore National Laboratory (LLNL) in Livermore, California. The tester delivers repetitive high voltage pulses to a series pair of flashlamps at levels closely simulating those encountered in normal operation. Each lamp pair is subjected to a pre-ionization and main pulse shot sequence, with two minute intervals between shots. This capability allows the manufacturer to test and evaluate the flashlamps for infant mortality and longevity before delivery to NIF [1]. All operations are under computer control with fully automated test and data acquisition capabilities requiring minimal operator input. The system is designed to operate continuously. Typical pre-ionization and main pulse outputs are Pre-ionization Pulse: V/sub chg/=27kV, I/sub peak/=3kA, E=2.4kJ, Pulse Width: (10%-90%)=200us Main Pulse: V/sub chg/=23kV, I/sub peak/=24kA, E=78.6kJ, Pulse Width: (10%-90%)=350us.