Enrofloxacin (ENFLX) is a fluoroquinoline antibiotic that is used in veterinary medicine-on cattle, pigs, poultry, fish, dogs and cats. Fluoroquinolines, although considered to be well-tolerated, may display a number of side-effects such as neurotoxicity, phototoxicity cardiotoxicity and hepatotoxicity. They also have the potential to induce Achilles tendon disorders such as tendinitis or even rupture. Molecular modelling analyses based on molecular mechanics, semi-empirical (PM3) and DFT (at B3LYP/6-31G* level) calculations show that neither ENFLX nor any of its metabolites is highly labile kinetically or extremely inert and that all the compounds have moderately low solubility in water except the terminal metabolite SCPFLX which has a much higher solubility. This means that the toxicity of ENFLX cannot be attributed solely to ENFLX or any particular metabolites. Although ENFLX and its metabolites are found to differ in the extent of electron-deficient regions on the molecular surface, because of relatively low kinetic lability, neither is expected to react readily with reduced form of glutathione and thus cause its depletion.