We evaluated the pharmacokinetics of ciprofloxacin in serum (n = 6) and urine (n = 4) in goats following a single intravenous administration of 4 mg/kg body weight. The serum concentration-time curves of ciprofloxacin were best fitted by a two-compartment open model. The drug was detected in goat serum up to 12 h. The elimination rate constant (¥â) and elimination half-life (t_1/2¥â) were 0.446 ¡¾ 0.04 h^-1 and 1.630 ¡¾ 0.17 h, respectively. The apparent volume of distribution at steady state (Vd_ss) was 2.012 ¡¾ 0.37 l/kg and the total body clearance (Cl_B) was 16.27 ¡¾ 1.87 ml/min/kg. Urinary recovery of ciprofloxacin was 29.70% ¡¾ 10.34% of the administered dose within 36 h post administration. In vitro serum protein binding was 41% ¡¾ 13.10%. Thus, a single daily intravenous dose of 4 mg/kg is sufficient to maintain effective levels in serum and for 36 h in urine, allowing treatment of systemic, Gram-negative bacterial infections and urinary tract infections by most pathogens.