Résumé : The influence of post-mortem autolysis on the histochemistry of succinate dehydrogenase, glucose-6-phosphate dehydrogenase and NADPH tetrazolium reductase has been studied in the scalp, axilla and pubis of 31 bodies of both sexes. Multiple surgical biopsies of each region served as controls. The post-mortem interval varied between 75 minutes and two months. Several test reactions were carried out, including the evaluation of the "nothing dehydrogenase". Mentioned in passing is the fact that the reaction performed in the absence of specific substrate brought to light the enzymatic richness of the putrefaction bacteria and might therefore well constitute a new means of staining microbes in histologic slides. In general, the study has shown that the two enzymes and the coenzyme are remarkably stable and that the enzymatic activities of the tissues provided by the biopsies are in no way different from those collected at the autopsies. There is one restriction, namely that of a possible, but statistically not proven, influence of autolysis on glucose-6-phosphate dehydrogenase in the granulosa of the scalp and the NADPH of the eccrine acini of the axilla. These findings do not agree with those of Braun-Falco and Winter, who undertook similar work on succinate dehydrogenase of the skin of the cadaver, but under totally different experimental conditions. It is concluded that the histochemical study of these oxidative enzymes in the skin of the cadaver is of no help in assessing the time of death. Goffin reached the same conclusion after investigating certain hydrolytic enzymes of the skin. However, the findings do open up new perspectives to researchers who can make extensive use of cadaver skin for their histo-enzymatic studies. This justified a topographical survey of each enzyme in the skin and its appendages. The results are, generally speaking, in accordance with those of the literature. A few divergences, however, are underlined and discussed. © 1973.