The first aim of the study was to investigate the pharmacokinetics of eight anticoagulant rodenticides (brodifacoum, bromadiolone, chlorophacinone, coumatetralyl, difenacoum, difethialone, flocoumafen and warfarin) in plasma and liver of the mouse after single oral administration. Eight groups of mice dosed orally with a different anticoagulant rodenticide in a dose equal to one-half the lethal dose 50 (LD50), were killed at various times up to 21 days after administration. The eight anticoagulant rodenticides were assayed in plasma and liver by an LC-ESI-MS/MS method. Depending on the compound, the limit of quantification was set at 1 or 5 ng/mL in plasma. In liver, the limit of quantification was set at 250 ng/g for coumatetralyl and warfarin and at 100 ng/g for the other compounds. The elimination half-lives in plasma for first-generation rodenticides were shorter than those for second-generation rodenticides. Coumatetralyl, a first-generation product, had a plasma elimination half-life of 0.52 days. Brodifacoum, a second-generation product, showed a plasma elimination half-life of 91.7 days. The elimination half-lives in liver varied from 15.8 days for coumatetralyl to 307.4 days for brodifacoum. The second aim of the study was to illustrate the applicability of the developed method in a clinical case of a dog suspected of rodenticide poisoning.