The influence of structural flexibility on the magnitude and orientation of reflected pressures produced by blast shocks is examined. Present formulations for blast pressures based upon a rigid-surface assumptions are found to be inaccurate for applications to flexible aerospace structures. The effects of elastic behavior of panel-type structures on a reflected shock pressures is studied. A parametric study is completed in which the effects of structural flexibility including panel deflection, rotation, and velocity on the magnitude of the reflected pressures is investigated. The dynamic deflections and initial panel velocity of a flexible moving panel are found to be important parameters that influence the values of reflected pressures, particularly for aircraft panels in the near vicinity of a weapon-blast or a rocket-plume overpressure.