Single-dose toxicokinetics of permethrin was investigated in broiler chickens.A total of 20 male broiler chickens were assigned at random to two groups of 10 at 30days of age. A single dose of 10mg/kg body weight of permethrin was administered intravenously to the first group; in the second group, the same dose was administered into the crop.Serum permethrin was measured using an electron capture detector and gas chromatography equipment. The derived serum permethrin concentration/time curve demonstrated that the distribution kinetics of permethrin was well described by a two-compartment open model.For intravenous permethrin administration, the half-life at phase (t(1/2)), mean residence time (MRT) and area under the concentration-time curve in 0 (AUC(0)) values respectively were 4.731.00h, 5.06 +/- 1.05h and 16.45 +/- 3.28mg/h/l. In contrast, the C-max, t(max), t(1/2,) MRT and AUC(0) values respectively of the group given intra-crop permethrin were 0.60 +/- 0.42 g/ml, 0.55 +/- 0.19h, 5.54 +/- 0.78h, 7.06 +/- 0.63h and 1.95 +/- 0.97mg/h/l. The bioavailability of permethrin was 0.11.For both administration routes, the residence time of permethrin in the body was short and the bioavailability of permethrin was low. These results are relevant for assessing the use and safety of permethrin.