Forensic pathologists are familiar with alcohol abusers, who are found dead and in whom the cause of death cannot be ascertained. In order to examine the possible role of ketoacidosis for the cause of death in this group of alcohol abusers, the concentrations of ketone bodies (acetone, acetoacetate, D-beta-hydroxybutyrate) were determined in post mortem blood specimens. Determination of the ketone body concentrations were made by a coupled enzymatic head-space gas chromatographic method. The material consisted of blood specimens from 131 deceased persons and was divided into three groups: Group 1: controls, 79 cases of non alcohol abusers; group 2: 35 cases of alcohol abusers with known causes of death and group 3: 17 cases of alcohol abusers without ascertainable cause of death. The geometric means for the sum of the ketone body concentrations in blood were: controls, 109 mumol/l; alcohol abusers with known causes of death, 152 mumol/l; and alcohol abusers without known cause of death, 590 mumol/l. The limit value between the controls and the group of alcoholics with unascertainable cause of death was by logistic regression found to be 531 mumol/l (343-1224 mumol/l). The term 'ketoalcoholic death' is, therefore, suggested, when the measured post mortem blood ketone body concentration in an alcoholic with otherwise unknown cause of death exceeds 531 mumol/l.