Background: Morphine and morphine-like molecules were identified in numerous mammalian tissues. In particularly, morphine was present in adrenal gland and in PC-12 cells, corresponding to the cell line derived from rat adrenal medullary chromaffin cells. Material/methods: Morphine-like compounds were isolated after a deproteinization followed by a reverse phase high pressure chromatography purification coupled to a UV detector. This alkaloid was identified using nano-eletrospray ionization quadripole time of flight tandem mass spectrometry. Results: We demonstrate the presence of a morphine-like molecule inside the bovine chromaffin cell secretory granules. This alkaloid was also detected into the secretion medium of primary chromaffin cells in culture following nicotinic stimulation. Conclusions: Our findings demonstrate that a morphine-like component is synthesized in chromaffin cells and secreted into the incubation medium upon stimulation. This finding strongly suggests that this material may be released from adrenal tissues in response to stressors.