Nano-porous semiconducting materials have been an intensive research field for many photovoltaic (PV) applications. The Gratzel-type dye-sensitized solar cell (DSSC) is one of the important devices of those applications. Using TiO2 nanocrystalline electrode, it achieved recently the best energy conversion efficiency (η) as high as 11%. ZnO has similar electronic properties with TiO2 including conduction band (CB) position and band gap, so it has been also regarded as a good candidate for DSSC. Moreover, various simple and effective synthetic routes have been developed for nanocrystalline ZnO materials, while the optimized nanocrystalline TiO2 colloid can be prepared only through the hydrothermal method until now. Nevertheless, ZnObased DSSCs showed PV properties much inferior to TiO2based devices, though some systems using big particles exhibit slightly improved properties. For instance, Fitzmaurice