Tri- and pentacyclic fluoroquinolones were synthesized by intramolecular cyclization of the corresponding 3-hydrazinopolyfluorobenzoylacrylates followed by substitution of fluorine atoms by amine residues. The antitumor activity of the resulting compounds was studied at the National Cancer Institute using cultures of 60 cell lines of nine groups, including leukemia, lung tumor, large intestine tumor, CNS tumor, melanoma, ovary tumor, renal tumor, prostate tumor, and breast tumor. Relationships between structure and antitumor activity were analyzed. In vivo experimental data from hollow fiber tests are presented for two derivatives