Magnetic interactions are induced between non-magnetic, vertically aligned tin dioxide nanowires under field-emission conditions. Vertically aligned nanowires of tin dioxide are synthesized along the [100] direction by pulsed laser deposition of an epitaxial (200) seed layer on c-cut sapphire substrates followed by vapor-liquid-solid growth using catalyst-assisted pulsed laser deposition method. Due to the dense arrangement of the vertically aligned ultra-long nanowires deposited in this study, magnetic interactions between the nanowires carrying parallel currents become significant within 1 μm radius and lead to their self-reorganization into conical tipi structures under field emission conditions. Optimization of the aerial density of the emission tips and reduction in the field screening effects upon self-reorganization of the nanowire array can account for the large field enhancement factor of 2.6 × 104 at low turn-on field of 3 V/μm.