The spectra-analysis of surface waves (SASW) method is a seismic method that can be used to determine elastic modulus profiles of pavement sections nondestructively. This method is based upon the theory of stress wave propagation in layered media. The dispersive characteristics of measured surface waves are used for determining the elastic modulus and thickness of each layer in the profile. This paper contains a description of the in situ testing technique and the in-house data reduction procedure used in conducting SASW tests. Emphasis is placed on demonstrating situations where SASW tests can be utilized more effectively than other nondestructive tests. For example, when bedrock is present at shallow depths or when the pavement layers are thin, use of the SASW method may be preferred. Two case studies illustrating the accuracy, sensitivity, and limitations of the method are also included.