Immunocomplexes from the blood serum of 129 autopsied males and females from newborn age up to 95 years were examined by means of the PEGIKEM test. In cases of sudden death without inflammatory changes the mean value of immunocomplexes x = 22.794, s = 23.426; in cases of death due to injury without inflammatory changes x = 22.935, s = 21.947. In sudden death with inflammatory changes x = 41.154, s = 50.97; in death due to injury with inflammatory changes x = 54.500, s = 34.757. In inflammatory changes the values of immunocomplexes are increased statisticaly significantly; in sudden death p = 0.0485, in death due to injury p = 0.0193 when compared with controls without inflammatory changes. In sudden death, no statistically significant differences were found between the age groups 0-1 year, 2-15 years and above 16 years. In sudden death and that due to injury, the lowest values of immunocomplexes were found in infants to 1 year of age. Increased values of immunocomplexes may also be found in cases without inflammatory changes and, in contrast to it, may be low in inflammatory changes. Dependence of immunocomplexes upon the duration of the postmortem period was neither proved nor excluded by means of the statistical method. It is suitable to examine immunocomplexes immediately after the withdrawal of blood sample, fluctuation of values may occur in vitro (in cases of drowning and phylonephritis). The examination of immunocomplexes in postmortem blood is possible and in some cases suitably supplements the spectrum of diagnostic methods.