Technology is described for reversible resistivity memory having a crystalline silicon bit line. In one aspect, a memory structure comprises a hollow pillar of crystalline silicon inside of reversible resistivity material. The crystalline silicon may serve as a bit line. The memory structure may further comprise conductive material that forms word lines coupled to the outer surface of the reversible resistivity material. A memory cell comprises a portion of the reversible resistivity material between the crystalline silicon and one of the word lines. In one aspect, the hollow pillar of crystalline silicon surrounds a gate oxide, which surrounds a conductive transistor gate. Thus, the hollow pillar of crystalline silicon may function as a channel of a transistor. In one aspect, the crystalline silicon has predominantly a (100) orientation with respect to an inner surface of the reversible resistivity material. In one aspect, the crystalline silicon is a single crystal.