Biochemical investigations performed in cases of mechanical asphyxia have provided diverging information over time. The purpose of the study presented herein was threefold: to investigate the postmortem stability of a series of molecules (thyroglobulin, iodothyronines, calcitonin, and parathyroid hormone) in blood after death, to determine the same molecules in a series of cases of suicidal hangings for which antemortem serum samples were available, and to measure the same molecules in postmortem serum obtained from different sampling sites thereby evaluating the distribution of these molecules in the specific samples. Preliminary results indicated postmortem stability of thyroglobulin, calcitonin, and parathyroid hormone levels, decreasing total and free T4 levels, and increasing total and free T3 concentrations. Our findings also showed that antemortem mechanical force applied to the neck region (hanging cases) may be accompanied by increased thyroglobulin in peripheral (femoral) blood, though a certain number of cases with nonincreased thyroglobulin levels may be observed. Lastly, our results revealed that hanging, manual, and ligature strangulation cases may be accompanied by increased thyroglobulin, total T3, and free T3 values in postmortem serum specimens obtained from blood sampled at different sampling sites, even in the absence of microscopically identified thyroid gland tissue damage. Such increases are more constant and important in arterial and venous blood samples obtained from sampling sites located in close vicinity of the thyroid gland.