It is well established that use of alcohol increases the risk of fatal injuries. The presence of blood alcohol in autopsied deaths is regularly encountered in medico-legal practices. The aim of this study was to investigate the prevalence and concentration of alcohol in 1539 medico-legal autopsies in two counties in northern Norway in the period 1973-1992, and the reporting of acute alcohol influence among these deaths to the official cause-of-death statistics. Blood alcohol concentration (BAC) >/=0.5 per thousand (50 mg/100 ml) was found in 47.6% (n=456) of violent deaths tested, and in 93% (n=426) of these the BAC was >/=1.0 per thousand. In 17.4% (n=55) of tested natural deaths the BAC was >/=0.5 per thousand. Acute alcohol-influenced violent deaths were under-reported to the cause-of-death statistics. Deaths by motor vehicle traffic accidents did not differ from other violent deaths in this respect. The under-reporting among violent deaths was 41% in cases with BAC >/=0. 5 per thousand and 37% where the BAC was >/=1.0 per thousand during the whole period. It is concluded that post-mortem BAC >/=0.5 per thousand, should be regarded as a possible contributory cause in all violent deaths, and reported accordingly.