The Acoustical Imaging Symposium series began in 1968. The 23rd meeting of the series will be held in Boston in April 1997. The symposium has focused on the engineering and physical-science aspects of acoustic imaging. This presentation will survey a selected number of topics presented at these symposia, including acoustical holography techniques, phase-only imaging, imaging with backward and forward propagation techniques, acoustic microscopy imaging, underwater imaging, seismic imaging, and other imaging techniques.