The pharmacokinetic behavior of marbofloxacin was studied in seven healthy goats and in the same goats with induced fever after single-dose intravenous (i.v.) administration of 2 mg/kg b.w. Fever was induced by the administration of Escherichia coli endotoxin. Drug concentration in plasma was determined by high-performance liquid chromatography (HPLC). Drug distribution was somehow altered by fever as febrile goats showed a volume of distribution at steady-state (Vss = 0.72 ± 0.15 L/kg) lower than normal goats (Vss = 1.19 ± 0.33 L/kg). The elimination of the drug was also modified. Total plasma clearance (Cl) decreased from 0.24 ± 0.12 L/kg/h in healthy animals to 0.13 ± 0.05 L/kg/h in animals with endotoxin-induced fever, which is related to an increase in the area under the plasma concentration–time curve (AUC). Consequently, mean residence time (MRT) was also slightly increased in sick animals (MRT = 5.28 ± 00.99 and 6.09 ± 01.45 h, in healthy and febrile animals, respectively).