The distinct features of pyroelectric studies of ferroelectric semiconductors (FES), by a dynamic method, are considered. The influence of illumination, external electric field and various thermal cycles on the pyroelectric response of FES are analyzed. The efficiency of FES, such as Ag3AsS3 and Sn2P2S6, for pyroelectric applications are demonstrated. The practical realization of the potentiality of FES for such purposes are discussed. © 1991, Taylor & Francis Group, LLC. All rights reserved.