Post mortem changes due to putrefaction sometimes make people wrongly consider the autopsy of a decomposed body as unrewarding. A 5-year retrospective study was conducted and included all types of decomposed body subject to medicolegal autopsy, excluding bone remains and charred bodies. Sociodemographic, medical, and forensic data were collected. In the 350 cases included, most were socially isolated mature males discovered at home. The cause of death was determined in 80% of cases, and the manner of death in 86.6%. Identification was considered effective in 99.7% of cases by the chief prosecutor. The authors show that such an autopsy usually answers most questions raised by the investigation but can also be a valuable tool in the prevention, making it possible to define a profile of persons at risk of dying alone. In addition, they underline that forensic scientists should be cautious in their identification of conclusion as diverging views regarding the concept of "presumed identity" may lead to ethical tensions between judiciary and prosecutors as well as the medical community.