The present invention relates to pressure-sensitive adhesive compositions which contain (A) hydroxyl group and alkylene oxide group containing acrylic copolymer and (B) a multifunctional isocyanate-based hardener, and form interpenetrating network structures when hardened, and polarizers and liquid crystal displays comprising the same. The pressure-sensitive adhesive compositions of the present invention exhibit superior durability, reliability, and workability and effectively prevent light leakage under high temperature and/or high humidity conditions. Particularly, the present invention provides pressure-sensitive adhesive compositions capable of significantly suppressing light leakage even in large size display devices, and polarizers and liquid crystal displays comprising the same.