An analytical method of fructosamine (glycated serum protein) determination in hemolytic samples from cadavers was investigated for the postmortem diagnosis of diabetes mellitus. Fructosamine level is usually measured by the reduction of nitroblue tetrazolium (NBT) using a spectrophotometer. This assay was significantly disturbed by more than 1 g/l hemoglobin, which strongly reduced NBT by the catalytic action of the sulfhydryl and glycated groups. Glycated and total hemoglobin levels were then determined simultaneously to exclude the interferences. Total protein concentration was analyzed to eliminate dilutional effects by hemolysis. With these modifications, corrected fructosamine levels in samples containing not more than 10 g/l hemoglobin could be estimated. The assay of such hemolytic samples from 32 cadavers indicated higher fructosamine values in diabetic group than in non-diabetic subjects and the postmortem degradation of the levels as previously reported.