Factor analysis (FA) was performed on quinolone derivatives with antibacterial activity to model relationships between molecular descriptors and microbiological activities determined on five bacterial cell lines (Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa, Staphylococcus aureus and Streptococcus pneumoniae). Molecular modeling studies were performed with the use of HyperChem software and MM+ molecular mechanics with the semi-empirical AM1 method. Factor analysis led to the extraction of two main factors, with the share of factor 1 amounting to about 76% and factor 2 to about 24% for all the parameters used in the statistical analysis. Moreover, FA results indicated that energy of orbitals lowest unoccupied molecular orbital, energy of ionization, electron affinity, electronegativity, maximum electron density, refraction and polarizability appeared to be descriptors important for the antibacterial activity of quinolones.