The data on 6-fluorо-1,4-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.