Provided are an aqueous resin dispersion of an ethylene-vinyl alcohol copolymer exhibiting excellent dispersion stability, a production method for the aqueous resin dispersion, a hydrophilization agent including the aqueous resin dispersion, a hydrophilization method using the hydrophilization agent, a metal material on which a hydrophilic coating has been formed, and a heat exchanger on which a hydrophilic coating has been formed. Specifically provided are: an aqueous resin dispersion comprising an ethylene-vinyl alcohol copolymer (A) and a radical polymer (B) having a structural unit derived from a radical-polymerizable carboxylic acid monomer (B1-1), wherein the content of the radical polymer (B) is 10-80 mass % relative to the total content of the ethylene-vinyl alcohol copolymer (A) and the radical polymer (B); a production method for the aqueous resin dispersion; a hydrophilization agent including the aqueous resin dispersion; a hydrophilization method using the hydrophilization agent; a metal material on which a hydrophilic coating has been formed; and a heat exchanger on which a hydrophilic coating has been formed.