Abstract: Following its metabolism in the liver, morphine and its metabolites can be directly eliminated in bile. Then, they undergo the enterohepatic cycle (EHC) and mostly reappear in the circulation. We report a case showing the presence of morphine in bile (21.3 μg/mL) and hair (4.8 ng/mg) but not in blood, urine or the liver of an addict who survived in hospital for about 144 h (6 days). These data would indicate that the EHC does not play any role about 144 h after the last injection, and directly confirms that gall bladder is a storage depot for morphine. They constitute the first report of a demonstration of the effect of the EHC on morphine bioavailability in an addict, and could be considered as indication, without supporting circumstantial evidence, that the morphine level in bile is related to chronic opiate use.