The reflection of light from a shock front at near grazing incidence is considered. It is found that under these conditions the calculated reflectivity may be significantly changed from the first-order approximation used by earlier workers, due to higher-order effects, namely attenuation, refraction, and multiple reflection. Asymptotic analytic expressions for the upper and lower bounds of the reflectivity are obtained.The error in the reflectivity introduced by deviation in the shock front from planarity is also calculated. Quantitative expressions valid in the grazing incidence limit, which may also be expected to give good order-of-magnitude results in the general case, are obtained.