Australian immigration detention centres are in secluded locations, some on offshore islands, and are subject to extreme secrecy, comparable with ‘black sites’ elsewhere. There are parallels between healthcare professionals working in immigration detention centres and healthcare professionals involved with or complicit in torture. In both cases, healthcare professionals are conflicted between a duty of care to improve the health of patients and the interests of the government. While this duality of interests has been recognised previously, the full implications for healthcare professionals working in immigration detention have not been addressed. The Australian Government maintains that immigration detention is needed for security checks, but the average duration of immigration detention has increased from 10 weeks to 14 months, and detainees are not informed of the progress of their application for refugee status. Long-term immigration detention causes major mental health problems, is illegal in international law and arguably fulfils the recognised definition of torture. It is generally accepted that healthcare professionals should not participate in or condone torture. Australian healthcare professionals thus face a major ethical dilemma: patients in immigration detention have pressing mental and physical health needs, but providing healthcare might support or represent complicity in a practice that is unethical. Individual healthcare professionals need to decide whether or not to work in immigration detention centres. If they do so, they need to decide for how long and to what extent restrictive contracts and gagging laws will constrain them from advocating for closing detention centres.