The pharmacokinetic properties of sarafloxacin were investigated after single intravenous (i.v.) and oral (p.o.) administration of 10 mg/kg body weight (b.w.) in allogynogenetic silver crucian carp at 24–26 °C. The plasma concentrations of sarafloxacin were determined by high-performance liquid chromatography. After i.v. administration, the plasma concentration–time data were described by an open two-compartment model. The elimination half-life (T 1/2β) was estimated to be 22.58 h. The volume of distribution, V d(area), was estimated to be 5.95 L/kg, indicating good tissue penetration of sarafloxacin in the fish. Area under the concentration–time curve (AUC) and total body clearance of sarafloxacin were 56.86 µg·h/mL and 0.18 L/h/kg, respectively. Following p.o. administration, the maximum plasma concentration (C max), T 1/2β, and AUC of sarafloxacin were 0.79 µg/mL, 46.68 h, and 16.58 µg·h/mL, respectively. Absorption of the drug was not good with a bioavailability (F) of 29.15 %. Based on a minimum inhibitory concentration (MIC) of 0.00625 to 0.045 μg/mL for susceptible strains, sarafloxacin p.o. administration at a dose 10 mg/kg could be efficacious against common pathogenic bacteria of fish.