The use of pyroelectric sensors for the detection of radiation induced thermal wave phenomena (the photopyroelectric effect) is reviewed. These sensors are compatible with most media-UHV, air, most liquids and solids-and have the potential for picosecond time resolution combined with a tremendous sensitivity. At first the signal generation process in such a sensor is briefly described and the importance of the ferroelectric material properties highlighted. The use of these devices as detectors of radiation-induced heating is then discussed in the time-resolved, and frequency-domain modes of excitation and detection and in a variety of spectral regions from radio waves to X-rays, electrons, ions and neutral particles. Condensed phase applications emphasizing the versatility and the unique properties of these detection schemes, as well as their inherent limitations will be presented. Typical applications in the thermal analysis and spectroscopy of thin films and the nondestructive evaluation of electronic materials are reviewed. Recent developments and future needs are finally discussed. © 1991, Taylor & Francis Group, LLC. All rights reserved.