This paper summarises the dimensions and immediate causes of officer deaths on-duty in Australia from the establishment of police forces in the 19th Century to 2007. Official police records were used to identify the year and the immediate circumstances of deaths. The results strongly support an emerging international knowledge base about police deaths: that up to three-quarters are "accidental" and as few as one quarter the result of an attack by an offender; that the very large majority of accidents involve motor vehicles; that in the post World War Two period officer fatalities have been declining as a proportion of police numbers as a result of improvements in procedures and technology; and that further reductions are obtainable through stricter application of a wider range of prevention strategies. The paper concludes by mapping out some key strategies, including curtailing speeding in police vehicles; keeping police off the road at vehicle stops and roadblocks; and better risk management procedures in raids, sieges, arrests and service of warrants.