The organic–inorganic hybrid material, [Na+(ClO4)−(C6H5NO3)(H2O)] n crystallizes in the triclinic space group P-1 with the unit-cell parameters a = 6.1756(3) Å, b = 7.3500(3) Å, c = 12.1415(6) Å, α = 100.386(4)°, β = 104.707(4)°, and γ = 97.069(4)°. In the crystal structure the picolinic acid N-oxide exists as a neutral molecule with very strong intramolecular O···H···O hydrogen bond between the carboxyl and N-oxide oxygen atoms. The O···O distance is 2.401(2) Å and the difference Fourier map shows clearly the position of the hydrogen atom approximately in the middle point between the oxygen atoms. The sodium atoms (which occupy two different centres of symmetry) are joined by water, perchlorate anion, and the carbonyl oxygen atom from picolinic acid N-oxide into 1D polymeric chain which extends along [100] direction. The neighbouring chains are connected by O(water)–H···O(perchlorate or picolinic acid N-oxide) hydrogen bonds into layers, which in turn interact with each other by means of short π···π dimeric interactions. The distance between the centroids of pyridine rings is 3.444 Å and the interplanar separation is only 3.195 Å. The sodium cations are joined by water, perchlorate anions, and the carbonyl oxygen atoms from picolinic acid N-oxide into 1D polymeric chain which extends along [100] direction.