Blood mephedrone concentration in dead patients is approximately 11 times higher than in non-fatal cases. This finding could serve as a stepping stone to the diagnosis of concentrations in clinical poisoning cases and deaths, especially in the treatment of poisoning patients. In more extensive prospective studies, further research is necessary to establish a standardized, real-time available methodology and validate the predictive value of mephedrone concentrations in the prognostic value of mephedrone concentrations.