The pharmacokinetic parameters and bioavailability of doxycycline were compared in four groups of six male turkeys each, after a single intravenous, oral, or intramuscular (thigh or pectoral muscle) routes at a dosage of 20 mg/kg b.wt. of doxycycline. HPLC with UV detection at 347 nm was used to estimate doxycycline concentrations. Following the intravenous injection, doxycycline obeyed a two-compartment open model, the distribution half-life time (t_1/2α), the elimination half-life time(t_1/2β), the body clearance (CL), and the volume of distribution (V_ss) were 0.235h, 10.49h, 0.132 mg/(μg/ml) and 2.00 L/Kg respectively. Following the extravascular administration, the maximal serum concentrations (C_max) of doxycycline in turkeys were 4.66 μg/ml, 6.17 μg/ml, and 5.61 μg/ml with time-to-peak concentration (T_max) of 2.80 h, 1.78 h, and 1.90 h and absolute bioavailability of 57.1%, 70.6% and 67.2% after oral, thigh, and pectoral muscle administration respectively. The MRT was 14.80 h, 18.48 h, 22.90 h, and 19.53 h after iv, oral, IMT, and IMP respectively. We recommend that the doxycycline should be injected into the thigh muscle in turkeys since it achieved high bioavailability and highest MRT, and longer t_1/2β.