Zn<sub>2</sub>GeO<sub>4</sub> is a novel transparent conductive oxide material, with an ultra-wide band gap of 4.5 eV, and rather good electrical conductivity. Zn<sub>2</sub>GeO<sub>4</sub> nano- and microwires grown by a thermal technique show two intense emission bands centered in the UV and VIS region, respectively. In this work, we have studied the correlation between luminescence and structural properties in undoped and Mg doped samples. The waveguiding behavior of the microrods has been assessed by the excitation with a 325 nm laser and analysis of the transmitted light along the structure. The intense white luminescence of Zn<sub>2</sub>GeO<sub>4</sub> nanomaterials makes them of interest as efficient phosphors for field emission displays.