Two postmortem cases are compared with regard to the role of mitragynine in the fatalities. A significant difference could be seen in the absolute concentrations of mitragynine detected for the two cases. A significant difference could be seen in the relative concentrations of mitragynine to its diastereomers between the two cases. Mitragynine was not the direct cause of death in either of the two cases, despite an extremely high blood mitragynine concentration in one of the two.