It is an object of the invention to provide a pressure sensitive adhesive for an optical film with which a pressure sensitive adhesive type optical film capable of suppressing bowing and light leakage caused by a stress accompanying a dimensional change of members such as an optical film, high in durability, excellent in handling ability in an aspect of a fabrication process thereof and good in quality can be obtained. There is provided a pressure sensitive adhesive for an optical film comprising: 100 parts by weight of a (meth)acrylic-based polymer (A) including an alkyl (meth)acrylate (a1) and a (meth)acrylic-based monomer containing a hydroxyl group (a2), as a copolymerizable component, in content in the range of from 0.01 to 5 parts by weight relative to 100 parts by weight of the alkyl (meth)acrylate (a1); 0.02 to 2 parts by weight of a peroxide (B); and 0.001 to 2 parts by weight of an isocyanate-based compound (C), the contents of the peroxide (B) and the isocyanate-based compound (C) being values relative to 100 parts by weight of the (meth)acrylic-based polymer (A).