The effects of pulsed irradiation on the response of materials are reviewed in terms of the basic principles behind the experimental and theoretical efforts in this area. A general background on the phenomena associated with pulsed irradiation in a fusion reactor environment is outlined. It is shown that the systems most likely to have significant dynamic response to pulsed irradiation will be the inertial confinement fusion reactors (ICFRs), and to a lesser degree, the near-term tokamak fusion reactors. A brief description of the magnitudes of radiation damage and the time scales over which damage occurs is given for various fusion reactor concepts. This sets the boundary conditions that need to be considered in analyzing radiation effects in pulsed fusion systems. The work on the primary damage state is reviewed, analyzing the effects of neutrons and ions on the instantaneous damage state of ICFRs. Since the energy deposition manifests itself in the form of damage and heat, the temperature and stress waves accompanying damage in ICFR walls are discussed. The state of knowledge on the microstructure evolution during pulsed irradiation is outlined in detail giving the theoretical principles and experimental observations. Finally, the relationships between the evolving microstructure and properties such as swelling, solute segregation, and irradiation creep in a pulsed irradiation environment are investigated.