 For two consecutive terms he served as a member of the CDBI Bureau.In 2010, he was nominated to UNESCO's International Bioethics Committee

In medical ethics, Dr. Trontelj's main interests were biomedical research on human beings, informed consent to medical interventions and research, brain death, organ donation, ethical questions in immunisation, artificial procreation, non-academic medical practices, vegetative state and states of minimal responsiveness, and end of life decisions.He also contributed to drafting of Slovenian laws on organ transplantation, biomedically-assisted reproduction, gene technology, mental health and patient's rights.