Engineering analysis of existing structures begins with having a well-founded understanding of as-built construction and existing conditions. Tomographic imaging is particularly attractive for evaluating massive sections because information may be gathered using any of a number of nondestructive methods including ultrasonic or sonic velocity, radar, and resistivity approaches. First developed in the 1930s for medical imaging, tomographic methods were adapted for geophysical exploration in the 1980s and for evaluating civil structures in the 1990s. Tomographic imaging is a computational technique which calculates the distribution of some parameter of interest within an interior region using measurements taken along the edges of the region. Evaluating civil construction with tomography involves large data sets of nondestructive information analyzed using an iterative process to provide two- and three-dimensional representations of characteristics within the section. The reconstructed image is used to show features concealed beneath the material’s surface including the location and extent of cracks, voids, material distress, identification of large, embedded steel elements, indication of density variations, and qualification of repair or retrofit procedures. This paper will review the history of the development of tomographic imaging approaches applicable to evaluating civil structures and show typical results used to evaluate concrete, monolithic stones, and masonry construction. Practical recommendations for acquiring pulse velocity information and conducting a tomographic analysis are included.