In the title heterodinuclear complex, [CuNa(C(8)H(7)O(3))(2)(ClO(4))(CH(3)OH)](n), the Cu(II) ion is five-coordinated by four O atoms from two 2-formyl-6-meth-oxy-phenolate anions and one O atom from a perchlorate anion in a distorted square-pyramidal geometry. The Na(+) ion is six-coordinated by four O atoms from two 2-formyl-6-meth-oxy-phenolate ligands, one O atom of a methanol mol-ecule and one O atom of a perchlorate anion. The perchlorate anions link the Na(+) and Cu(II) ions, forming a chain along [010]. O-H⋯O hydrogen bonds connect the chains. π-π inter-actions are present between the benzene rings [centroid-centroid distances = 3.566 (2) and 3.702 (2) Å]. The O atoms of the perchlorate anion are disordered over two sets of sites, with an occupancy ratio of 0.481 (8):0.519 (8).