In the title complex, [La(C(5)H(3)N(2)O(2))(C(2)O(4))(H(2)O)(2)](n), the La(III) ion is coordinated by one N and three O atoms from two pyrazine-2-carboxylate ligands, by four O atoms from two oxalate ligands and by two O atoms of two water molecules, displaying a distorted bicapped square-anti-prismatic geometry. The carboxyl-ate groups of pyrazine-2-carboxyl-ate and oxalate ligands link the lanthanum metal centres, forming layers parallel to (10). The layers are further connected by inter-molecular O-H⋯O and N-H⋯O hydrogen-bonding inter-actions, forming a three-dimensional supra-molecular network.