The invention provides a circuit arrangement for igniting gas discharge flash tubes including a gas discharge flash tube having two-spaced-apart electrodes, a pulse forming network and a voltage generator for supplying ignition pulses and tube burning pulses during simmer mode, the arrangement having a resonant circuit connected in circuit between the electrodes and the voltage generator, wherein the voltage generator provides the resonant circuit with AC high frequency voltage for producing gradually increasing amplitudes of an AC voltage until ignition voltage is achieved and for supplying AC voltage of a lower level in comparison to the level of the ignition voltage, for sustaining the burning of the tube during the simmer mode.