An adhesive of the invention for polarizing plates used for forming an adhesive layer in a polarizing plate in which a polarizer and a transparent protective film is are adhering with each other via the adhesive layer, wherein the adhesive for polarizing plates is an aqueous solution containing a polyvinyl alcohol-based resin having an acetoacetyl group and a crosslinking agent, and the aqueous solution has a pH of 4.3 or less. The adhesive of the invention for polarizing plates is good in durability and long in pot life.