ZnO films were synthesized by pulsed laser deposition (PLD) on GaAs and alpha-Al2O3 substrates. The properties of ZnO films on GaAs and alpha-Al2O3 have been investigated to determine the differences between epitaxial and textured ZnO films. ZnO films on GaAs show very strong emission features associated with exciton transitions as do ZnO films on alpha-Al2O3, while the crystalline structural qualities for ZnO films on alpha-Al2O3 are much better than those for ZnO films on GaAs. The properties of ZnO films are studied by comparing highly oriented, textured ZnO films on GaAs with epitaxial ZnO films on alpha-Al2O3 synthesized along the c-axis.