INTRODUCTION AND AIMS: The pathophysiology and time-course of coagulopathy post major burns are inadequately understood. The aims of this study were to review the incidence of acute coagulopathy post major burns, potential contributing factors associated with this coagulopathy and outcome of patients who developed early coagulopathy. METHODS: A retrospective review of all patients with major burns (≥20% total body surface area (TBSA)) presenting to a tertiary burns referral centre was conducted. Data on demographic, injury characteristics and fluid resuscitation practices were recorded and tested for association with coagulopathy (INR>1.5 or aPTT>60 s) at hospital presentation and within 24 h of burns injury. Mortality, intensive care unit (ICU) admission, mechanical ventilation and blood and blood product usage were primary endpoints. RESULTS: There were 99 patients who met the inclusion criteria with 36 (16) %TBSA burns. Coagulopathy was present in only three patients on presentation, but 37 (37%) patients developed early onset (within 24 h of injury) coagulopathy. Early onset coagulopathy was independently associated with %TBSA burnt (p<0.001) and volume of fluid administered (p=0.005). Early onset coagulopathy was associated with higher volumes of blood and blood product administration, ICU admission and prolonged mechanical ventilation. CONCLUSIONS: Post major burns, a very low proportion of patients presented with coagulopathy, but a substantial proportion of patients developed coagulopathy within 24 h. This and the association of coagulopathy with the volume of fluid resuscitation suggest dilution as a major cause of the early coagulopathy of major burns.