In the title compound, [Cu(C₁₅H₂₀N₂O₄)]_n, the copper(II) coordination is square planar. The anionic L-tyrosyl-L-leucinate ligand binds in an N,N′,O-tridentate mode to one Cu^II cation on one side and in an O-monodentate mode to a second Cu^II cation on the other side, thus defining –Cu–O–C–O–Cu′– chains which run along the a axis. These chains are held together by a strong hydrogen bond involving the hydroxy H atom.