Aluminum doped zinc oxide (ZnO:Al) is useful as a transparent conducting oxide, and have been considered as a potential substitute for indium tin oxide (ITO) in some applications. It is normally produced through sputtering, but metal organic vapour deposition (MOCVD) can also be a useful method of fabrication. We have investigated how the properties of ZnO:Al are affected by the various parameters and principles of MOCVD growth. In this work we focus particularly on the effects of II/VI ratio and flow parameters on Al incorporation, and resulting optical and electrical properties.