The aim of this paper is to determine the correlation between carbonized fire victims' carbon-monoxide (CO) blood concentration and the cause of death. We have reevaluated and analyzed the causes of death over a 10-year period regarding CO concentrations and atherosclerosis. We have considered the possible usefulness of low CO concentrations as a vital sign in smokers and non-smokers. The study included the retrospective analyzes of 73 autopsy reports of carbonized bodies. All the autopsies were carried out in the Institute of Forensic Medicine in Belgrade over a 10-year period (1990-1999). The investigation included 53 men and 20 women (chi(2)=19.83, p<0.001) with an average age of 41.40+/-21.35 years. We found 10 cases of deadly carbon-monoxide poisoning, but further analysis of CO concentrations revealed 6 more cases in which CO poisoning could be considered. We found a statistically significant relationship between carboxyhaemoglobin concentration above 10% and the aspiration of soot (chi(2)=6.41, p<0.01). In five cases with serious atherosclerosis, the concentration of carboxyhaemoglobin was above 20%, although these concentrations can be accepted as the cause of death. Half of the deceased, in the moment of death were under the influence of alcohol and 19 of them had a blood alcohol concentration above 1 pro mille.