The use of petrographic thin sections to examine archaeological sediments has centered on the study of detrital and chemical components of the material. There has been relatively little effort made to study botanical remains—particularly charcoal—with this technique. This paper illustrates that millimeter-size or even smaller fragments examined in undisturbed, artificially indurated samples, which normally would escape collection with standard flotation and sieving techniques, can furnish significant paleobotanical information about the types of vegetal matter found in a site. Samples from cave sediments in Israel and an open-air site in Canada are presented. © 1994 John Wiley & Sons, Inc.