In the title metal-organic polymeric complex, [CuI(C5H5N3O)] n , the asymmetric unit is composed of one monomer unit of the polymer and one Cu(I) atom linked to one iodide anion and one pyrazine-2-carboxamide mol-ecule. The Cu(I) atom is in a distorted tetra-hedral coordination completed by one pyrazine N atom of the pyrazine-2-carboxamide ligand and three iodide anions. The polymeric structure adopts a well-known ladder-like motif of {CuNI3} tetra-hedra running in the b-axis direction. The mol-ecules of the organic ligand are connected via medium-to-strong N-H⋯O and N-H⋯N hydrogen bonds and weak π-π inter-actions [the distance between two parallel planes of the rings is 3.5476 (14) Å and the centroid-centroid contact is 4.080 (2) Å]. The title compound has a relatively high decomposition temperature (564 K) as a result of relatively strong covalent and non-covalent inter-actions inside and between the chains.