Molecular dynamics computer simulations have been made on the para-electric phase of solid sodium nitrite and on the melt. The interionic-force model used in the calculations is based on a rigid-ion representation of the electrostatic interactions, supplemented by a set of atom-atom potentials. Reorientation of the anions in the solid is shown to occur predominantly about an axis parallel to the crystallographic c-direction. The structure of the molten salt is found to be characterized by a high degree of local octahedral coordination. Agreement with the available experimental data is satisfactory.