The unregulated substance kratom, which contains the psychoactive compound mitragynine, is sold in Germany as a dietary supplement and induces various effects, ranging from stimulating to sedative, depending on the dosage. The spectrum of side effects includes dizziness, seizures and respiratory depression. Internationally, several fatalities associated with kratom (both mixed and mono-intoxications) have been reported. This paper presents the first case of a fatal mitragynine mono-intoxication in Germany.