A nonvolatile memory device, a method of fabricating the nonvolatile memory device and a processing system including the nonvolatile memory device. The nonvolatile memory device may include a plurality of internal electrodes that extend in a direction substantially perpendicular to a face of a substrate, a plurality of first external electrodes that extend substantially in parallel with the face of the substrate, and a plurality of second external electrodes that also extend substantially in parallel with the face of the substrate. Each first external electrode is on a first side of a respective one of the internal electrodes, and each second external electrode is on a second side of a respective one of the internal electrodes. These devices also include a plurality of variable resistors that contact the internal electrodes, the first external electrodes and the second external electrodes.