Disclosed is an adhesive for packaging materials being in a form of an aqueous dispersion including an acid-modified polyolefin resin containing a (meth)acrylic acid ester component, polyvinyl alcohol and an aqueous medium, wherein the content of polyvinyl alcohol is 0.1 to 10 parts by mass in relation to 100 parts by mass of the acid-modified polyolefin resin. Also disclosed is a packaging material using the adhesive wherein a barrier layer, an adhesive layer formed of a coating film obtained from the adhesive, and a sealant layer are laminated in this order.