The reaction of hydroxylamine hydrochloride with isatin in ethanol, catalysed with HCl and neutralized with Na2CO3, yielded the one-dimensional coordination polymer, catena-poly[[[aquasodium]-di-μ-aqua-[aquasodium]-bis(μ-2-oxoindoline-2,3-dione 3-oximato)] tetrakis(oxoindoline-2,3-dione 3-oxime)], {[Na(C8H5N2O2)(H2O)2]·2C8H6N2O2}n. The NaI atom has a six-coordinate distorted-octahedral environment. Isatine-3-oximate O atoms and water molecules bridge adjacent Na atoms, forming a one-dimensional polymeric structure parallel to [100]. Each isatine-3-oxime dimerizes through N—H...O interactions and in addition each oxime is linked to a coordination polymer. Thus, coordination polymers are linked by O—H...O and O—H...N interactions from isatine-3-oxime dimers, building a two-dimensional network parallel to [110].