One in 10 of all deaths in Australia last year were caused by dementia, according to the Australian Bureau of Statistics (ABS).
It remained the leading cause of death in the country with more than 19,000 deaths from dementia, including Alzheimer's disease, in 2025.
ABS head of mortality statistics Lauren Moran said the fatal condition became the leading cause of death in 2024, and has remained at the top of the list ever since.
Broken down by gender, it has been the most deadly condition among women for the last 10 years.
Australian National University's Liz Allen, a demographer, said Australia was an aged society rather than an aging one, where deaths will soon outnumber births.
"So in other words, we're living longer and we're living healthier lives. And as a result, the causes of death are dominated by things like dementia and Alzheimer's," she said.
The second leading cause of death in 2025 was ischaemic heart disease, a condition where the heart is starved of oxygen, accounting for about 8 per cent of deaths.
But the number of Australians who die from this condition is now the lowest it's been since 1968.
The other top five leading causes of death included cerebrovascular diseases which affect the brain, lung cancer and chronic lower respiratory diseases.
Combined, those five conditions represent one third of all deaths in Australia.
There was a slight drop in suicides in the overall population, however, they rose for Aboriginal and Torres Strait Islander people.
Mortality rate back to pre-COVID trend
Australia's mortality rates declined in 2025, which has put the nation's long-term trend back to its pre-pandemic levels.
The median age of death in Australia was 81.9 years, with more than two thirds among people aged 75 years or older.
The ABS' age-standardised death rate fell for both men and women in 2025.
It refers deaths per 100,000 standard population, which have returned to pre-COVID-19 levels.
Ms Moran said with an aging population, the number of deaths was likely to increase over time but decline relative to population size.
"The COVID-19 pandemic temporarily disrupted that pattern, but these rates indicate that Australia's mortality patterns are returning to the long-term trend of declining death rates," she said.
Despite overall population trends, the leading cause of death for Aboriginal and Torres Strait Islander people remained ischaemic heart diseases across the country.
The age-standardised death rate for Indigenous people also rose by 5.2 per cent in 2025.
Suicide rates fall, drug deaths rise
A total of 3,283 people died by suicide in 2025, a slight decrease on the previous year, with men accounting 73.9 per cent of those deaths.
The median age of people who died by suicide was 45 years old.
It remained the leading cause of premature death for both males and females, however, male suicide has fallen to its lowest level since 2016.
There were also 320 registered deaths by suicide of Aboriginal and Torres Strait Islander people, the highest in this ABS time series.
The rise was highest among Indigenous women, where suicides increased by 42.
The ABS has pointed out the data is preliminary and is expected to change as coronial investigations are finalised.
Suicide Prevention Australia's Chris Stone said there were reasons to be optimistic about suicide rates for men but there had not been enough of a change in the numbers.
There was also a rise in drug-induced deaths in 2025, increasing to 2,063 from 2,007 the previous year.
Ms Moran from the ABS said the median age for drug-induced death was 48.2 years, which was almost 15 years older than when its mortality rate peaked in 1999.
Last year, there were 779 drug-induced deaths involving stimulants compared to 504 deaths in 2021.
