A pulsed-beam technique has been developed to measure the ion-induced secondary-electron emission from insulating films. The technique, which circumvents conventional specimen heating, consists in determining the target and collector currents in a pulsed ion beam at a varied retarding collector potential, followed by neutralizing the surface change at each pulse interval with a beam of low-energy electrons. Measurements have been made with this technique on MgO films on conductive substrate, using neon and argon ions at 200-eV energy. The secondary-electron yield γi for the electronspectroscopically clean MgO films was found to be 0.45 and 0.05 for Ne+ and Ar+, respectively.