About 6% of older people in the UK are immigrants. Concentrated in deprived inner-city areas, their numbers are rising rapidly, with the ageing of those arriving after the Second World War. Cultural, language and educational differences cause problems in studying this group's mental health. Idioms of distress may affect presentation, help-seeking behaviour and acceptability of treatment. Ethnic elders may be considered vulnerable to depression because of socio-economic deprivation, immigrant status and old age but studies are contradictory and may use inappropriate screening instruments. Relatively few consider immigrant status and dementia. Uncontrolled hypertension could relate to higher dementia rates in Black immigrants which are not reflected in the country of origin. No genetic risk has been found. There is potential for prevention in this population.