Coroners' data on blood alcohol concentrations of fatally injured crash victims in New South Wales are examined. Published data from Victoria and Queensland are summarised. It is found that in New South Wales the blood alcohol concentrations of a large proportion of all fatally injured drivers and riders remains unknown. An exact estimate of the proportion of drivers and riders with a blood alcohol concentration above the legal limit of 0.08g/100m1 cannot be obtained. However, a range of estimates may be obtained by assuming that the unknown blood alcohol concentrations may all be either above or below the legal limit. Based mainly on data collected from New South Wales coroners' courts, and supported by data from other States, it is estimated that 30% to 60% of all drivers and motorcyclists who die as a result of a motor traffic crash have a blood alcohol concentration of 0.08g/100m1 (.08%) or more.