Impact-echo is an acoustic method for nondestructive evaluation of concrete and masonry, invented at the U.S. National Bureau of Standards (NBS) in the mid-1980's, and developed at Cornell University, in Ithaca, New York, from 1987-1997. This article provides a brief description of the method, information about test equipment manufactured by Impact-Echo Instruments, LLC of Ithaca, New York, a description of a new book about impact-echo, and a list of case studies describing a variety of applications. In December of 1997 the American Society of Testing Materials (ASTM) approved a new standard entitled, "Standard Test Method for Measuring the P-Wave Speed and the Thickness of Concrete Plates Using the Impact-Echo Method." This standard will appear in the 1998 Annual Book of ASTM Standards.