The present invention relates to a pressure-sensitive adhesive tape or sheet having a light-reflective property and/or a light-shielding property, which comprises a base material and at least one pressure-sensitive adhesive layer disposed on at least one surface of the base material, in which the pressure-sensitive adhesive layer is formed by an acrylic pressure-sensitive adhesive composition containing an acrylic polymer (a) and a low-molecular weight polymer component (b) which contains, as a principal monomer component, an ethylenic unsaturated monomer having a glass transition temperature of from 60 to 190.degree. C. when it is formed into a homopolymer and having a cyclic structure within the molecule thereof, and which has a weight-average molecular weight equal to or higher than 3,000 but lower than 20,000; in which the pressure-sensitive adhesive layer has a gel fraction of from 51 to 75 wt % and a temperature, at a maximum of loss tangent (tan .delta.), of from -14 to 25.degree. C.; and in which the pressure-sensitive adhesive tape or sheet has a reflectance of 60% or higher on at least one surface thereof and/or a transmittance of 0.3% or lower.