Anticoagulants are widely used pesticides in agriculture against rodents. The emergence of strains of rats resistant to warfarin led to the introduction of a new group of anticoagulant rodenticides: derivatives of 4-hydroxycoumarin (Brodifacoum, Bromadiolone, Difenacoum ...). The deliberate ingestion of large quantities of these products known by their long duration of action causes a disruption of several weeks to several months of hemostasis. CASE REPORT: 20 year old comes to the emergency CAMU with a tremor and coma, requiring intubation and its implementation under mechanical ventilation. At 24 h after awakening, we note the presence of hematuria associated with a collapse of prothrombin (16%), prolonged partial thromboplastin time kaolin (T/M: 30s/50s), a collapse of fibrinogen (1.2 g/l) with a reduction factor of the Vitamin K dependent clotting II, VII, IX and X. The toxicological analysis of patient urine by HPLC shows the presence of brodifacoum CONCLUSION: Brodifacoum poisoning is relatively serious. Research and dosage of anti-vitamin K anticoagulants by HPLC with diode array detector, must be requested before any disturbance of hemostasis of undetermined origin. Treatment with vitamin K should be installed early in effective dose from the decreased prothrombin and must be prolonged.