The data on 6-fluoro-l,4-dihydroquinolin-4-oxo-3-carboxylic acids and their structural analogues accumulated in the literature for the last 10-15 years are reviewed. Synthetic approaches to the quinolone system, as well as all kind of structural modifications by incorporating substituents into 1-8 positions or by means of annelation have been discussed. The “structure-activity” relationships for antibacterial fluoroquinolones, as well as the data on other types of biological activity for the family of bi- and polycyclic fluoroquinolones are presented. The formation of complexes of fluoroquinolones with metals and their applications have been considered. The bibliography - 377 references.