In Norway it is becoming less common for the forensic pathologist to be called to the scene of a crime. When a vitreous humour fluid sample is taken where the body is discovered and the ambient temperature is recorded, the post mortem interval (PMI) can be estimated based on the levels of Hypoxanthine (Hx) and potassium (K+). When the sample is taken at the autopsy it is impossible to estimate PMI without knowledge of the temperature during transportation and storage of the body. This project thesis looks at the possibility for a forensic pathologist to determine PMI based on vitreous humour sampled during autopsy using adaptations of Rognum et al’s algorithms for estimation of PMI. The adaptions are evaluated on 17 cases from Institute of Forensic Medicine, University of Oslo, in which time of death is known. In the cases included in this thesis, the PMI and the different temperatures the body had been kept in were known. We solved Rognum et al’s two algorithms with Hx and K+ as unknown and used them to calculate a theoretical level of Hx and K+ at the time of sampling. We further compared the calculated levels of Hx and K+ with the measured levels and calculated the correlation coefficient. The correlation coefficients were between 0.809 and 0.958, giving explanation percent from moderate (65%) to good (94%). This indicates that the method could be used with caution when vitreous humour is taken during autopsy, if you have information of the varying temperatures during transport and handling of the body. Further improvement of the method should be done using more accurate recording of ambient temperature on the scene of crime and during transport and storage before the autopsy. The main conclusion from this project thesis is that so far, no improvement of methods for estimating PMI after the transport of the dead body to the mortuary may replace the forensic pathologist going to the scene of crime.