The uniaxial compressive strength (UCS) of rock material is one of the important mechanical parameters widely used for design, analysis and modeling in geotechnical engineering. Determination of UCS is destructive, expensive and time consuming. Recent trends have shown that ultrasonic velocity testing is a viable option for the prediction of UCS, considering that ultrasonic velocity testing is non-destructive, relatively inexpensive, fast and easy to conduct. This research presents a simple and reliable correlation to predict UCS from sonic velocity slowness determinations for schist. A total of 26 ultrasonic and uniaxial compressive strength tests were conducted to establish a correlation of UCS and sonic velocity slowness (1/Vp). The determined correlation is expressed as UCS = 1144.9 e-11183·(1/Vp) with coefficient of determination of 0.93. © 2015 ejge.