Building blocks for the synthesis of monofluorinated organic compounds are reviewed. The synthetic potential of polyhalomethanes, sulfur- and phosphorus-containing building blocks, difluoroethene, polyhaloethanes, fluoroacetic acid derivatives, and other compounds are described. Pericyclic reactions involving fluorinated compounds and application of the methodology of building blocks to the synthesis of monofluorinated pharmaceuticals and analogs of natural compounds are considered. The review with 317 references covers mainly the literature from 1996 through 2007.