Immigration is increasing and government policies are shifting. Clinicians need to be aware of the mental health needs of immigrants and the challenges of delivering appropriate care. In certain circumstances there are potential conflicts between doctors' clinical, ethical and legal responsibilities. Detention of refugees and asylum seekers may have a detrimental effect on mental health and can result in significant psychiatric morbidity. Ongoing management of foreign nationals following hospital treatment may be complicated by the threat of deportation and its implications for the patient's mental health.