Surface acoustic wave(SAW)devices with 64 μm wavelength were fabricated on a zinc oxide (ZnO)film deposited on top of an ultra-smooth nanocrystallinediamond(UNCD) layer. The smooth surface of the UNCDfilm allowed the growth of the ZnOfilm with excellent c-axis orientation and low surface roughness, suitable for SAW fabrication, and could restrain the wave from significantly dissipating into the substrate. The frequency response of the fabricated devices was characterized and a Rayleigh mode was observed at ∼65.4 MHz. This mode was utilised to demonstrate that the ZnO/UNCD SAWdevice can be successfully used for microfluidic applications. Streaming, pumping, and jetting using microdroplets of 0.5 and 20 μl were achieved and characterized under different powers applied to the SAWdevice, focusing more on the jetting behaviors induced by the ZnOSAW.