Introduction. The positive diagnosis of death is an important task in forensic medicine. It can be established by the forensic doctor or any other doctor of another specialty. The pathologist is often asked for an opinion on postmortem interval (PMI) based on the pathological findings. Estimating the time of death is of a great importance for the criminal investigation bodies, in regards to the possibility of justifying a version of actions, to gather evidence that can support or deny the states of action of suspect in a crime. Aim of the study. Finding the best methods that can provide us with accurate information regarding the estimation of death time. Materials and methods. Bibliographic sources (Hinari, Goali, Medscape, University Library, Color Atlases). Results. The time of death can be approximately estimated based on the supravital reaction (mechanical or electrical muscular excitability, pharmacological excitability of the iris muscle); cadaverous changes: early (dehydration, cooling, livor mortis, rigor mortis) and belated changes (putrefaction), destruction by animals or insects/entomology studies (flies); biochemical changes (level of potassium in the vitreous body or CSF). There are a lot of extrinsic (temperature, humidity, environment) and intrinsic (cause of death, weight, comorbidities) factors that influence the process of estimating the postmortem interval and the error ranges for the majority of these approaches are uncomfortably large. Conclusions. The exact time of death can not be estimated. For a better result it is advised to use more than one method at a time. While none of the changes after death is capable of providing a precise marker of time since death, the most reliable would appear to be related to the cooling of the body after death, using Henssge`s Nomogram (which can be used at the death scene). The more time passes, the difficult it is to determine the PMI. For bodies older than 3 days it is the best to determine the time of death by using the entomology research, using the stages of evolution of the insects.