Reviews recent research on fluorine-containing, biologically relevant molecules in biology and medicinal chemistry. Reports applications of bioactive organofluorine compounds as enzyme inhibitors, antithrombotics, anticancer agents, antiviral agents, antibacterials, central nervous system agents, and antifungals and antimalarial agents. Discusses the use of fluorine-containing amino acids as probes for investigating biomedical problems, including applications in fluorine-19 NMR, neurotransmission investigations, and fluorine-18 labeled tracers for positron emission tomography.