Abstract: Levofloxacin is a third generation fluoroquinolone with excellent tissue penetration and efficacy against respiratory and urogenital bacterial infections. In the present study, disposition kinetics of levofloxacin was studied in cattle calves following an intravenous (i.v.) and intramuscular (i.m.) administration at a dose rate of 10 mg kg-1. Blood was collected at predetermined time intervals and plasma was separated. Plasma concentrations of levofloxacin were determined using the HPLC assay method (R2 = 0.999). Plasma concentration versus time data was subjected to compartmental pharmacokinetic analysis using nonlinear iterative computer software “PHARMKIT”. Following intravenous and intramuscular administration of levofloxacin in cattle calves (10 mg kg-1), the plasma concentration versus time data of levofloxacin was best described by two-compartment open model and one-compartment open model with first order absorption rate constant with modest bioavailability values, respectively. The mean values for t½α and t½β were 0.05±0.01 h and 2.12±0.21 h, respectively for i.v. route. The values of AUC, Vdarea and ClB were found to be 29.32±1.19 μg mL-1 h, 1.05±0.10 L kg-1 and 0.34±0.01 L h-1 kg-1, respectively while the ratio of drug concentrations between the tissues and plasma (T/P) was 4.47±02.09. For i.m. route, the mean (±SE) values of t1/2Ka, t½β, AUC, MAT, MRT and F were found to be 0.51±0.09 h, 2.76±0.36 h, 18.43±2.15 μg mL-1 h, 1.85±0.46 h, 4.72±0.72 h and 62.65±5.99%, respectively. Based on the pharmacodynamic indices, the optimal dose of levofloxacin in cattle calves may be proposed as 10 mg kg-1 b.wt. repeated at 24 h interval preferably by intravenous route for treating common microbial infections of veterinary importance.