New interest in zinc oxide has developed since it has been discovered to be piezoelectric. In line with thisinterest the zero field adiabatic elastic moduli have been measured. A high frequency, 60 to 500 Mc ultrasonicpulse technique was employed. Two crystals with sufficiently high conductivity to effectively shortthe electric field were available for the measurements.A density of5.676 g/cm3was used to calculate the zero-field adiabatic elastic moduli. This density wastaken as exact with reference to the error limits.The moduli in units of1012 dyn/cm2at 25°C are:c11E = 2.097 ±0.1%,c12E = 1.211 ±0.15%,c13E = 1.051 ±0.15%,c33E = 2.109 ±0.1%,c44E = 0.4247 ±0.1%,c66E = 12(c11E−c12E) = 0.4429±0.1%.