Despite the significant number of studies conducted on periodic structures and frequency selective surfaces, few studies have examined the power handling capability of these structures in any detail. In this paper, we examine the transient power handling capability of a class of frequency selective surfaces composed entirely of non-resonant constituting elements. The effects of various design parameters on the peak power handling capability of the devices are investigated and methods for increasing their power handling capability are proposed. These methods are used to design a high-power microwave FSS, which is expected to be capable of handling power levels as high as 1.0 MW/cm2.The transient power handling capability of these structures is examined experimentally in a waveguide environment using a high-power magnetron source.