In the period from January 1986 through April 1993, 47 cases with diabetes mellitus were autopsied at the Institute of Forensic Medicine, Odense University. In 26 cases, the diabetes had been treated with insulin, in 21 cases with oral medication or diet only. In eight insulin-dependent cases, tubular vacuolation was found in the kidneys, the so-called Armanni-Ebstein lesions. The circumstances of death and postmortem analyses of blood, urine and/or vitreous humor supported a presumed diabetic coma as the cause of death in these eight cases. Of the remaining 39 cases, six were too putrefied for histologic examination. In the remaining 33 cases and in a series of 20 non-diabetics, the cause of death was ascertained as illness (other than diabetes), traffic accidents, drowning or intoxication. In none of these cases was a diabetic coma suspected, and none of these cases showed tubular vacuolation in the kidneys. The authors conclude that tubular vacuolation of the kidneys strongly indicates death in diabetic coma.