The present review records the known structures of more than 80 organic compounds containing halogens, which may be considered naturally occurring. The format of the review is based on the viewpoint of biochemists. Compounds containing one type of halogen atom have been placed in one of four major division, i.e., structures possessing fluorine, chlorine, bromine or iodine covalently bonded to carbon. Within each major division molecular structures are given along with the species from which the compounds have been isolated, The biological significance, if any, is also mentioned.