It has been established in previous papers that stress wave attenuation measurements performed on concrete are very sensitive to the presence of damage located along the wave path. In this paper, a modified form of this concept is introduced in a self-compensating measurement scheme: surface wave transmission is obtained, across a range of frequencies, between two sensing points on the surface of a concrete specimen. The obtained signal transmission values are independent of the type of wave transmitter and receiver used. An experimental test series on a range of concrete slabs containing notches and controlled cracks of varying depths is described. The cracks are generated by subjecting the slabs toexure using a closed-loop loading procedure. The actual depth of each generated crack is determined with the laser-based phase measurement interferometry technique. Self-compensating wave transmission measurements are performed across the discontinuities (notches, open cracks, and closed cracks) and are shown to be repeatable and sensitive to the presence of notches, and even tightly-closed cracks. A relationship between the wave transmission and the crack depth normalized with respect to propagating wavelength is noted. This relationship appears to be largely unaffected by the type of concrete and the nature of the discontinuity. The results demonstrate that self-compensating wave transmission measurements show excellent potential for sensitive detection and sizing of surface-breaking cracks in concrete structures. Copyright © 2000, American Concrete Institute. All rishts reserved.