Scots living in the poorest parts of the country are three times more likely to die before they reach their 25th birthday than those in the most affluent communities, new research has revealed.
Campaigners said the "shocking" findings highlight the need for more action to tackle poverty and inequality.
Aberlour Childcare Trust, which works with vulnerable young people, commissioned Dr Morag Treanor, Professor of Child and Family Inequalities at Heriot-Watt University in Edinburgh, to carry out the research.
The study, which was the first of its kind, revealed males up to the age of 24 were three times more likely to die from external causes than girls and young women.
Meanwhile, males and females in the poorest parts of society were three times more likely to die from external causes than the least deprived, it found.
The study looked at Scottish mortality records for the period 2011 to 2017, with the research focusing on deaths from external causes - such as traffic accidents, suicides and fatal accidents, including some drug and alcohol-related deaths, as well as deaths resulting from neglect, maltreatment, assault or violence.
Prof Treanor said: "What we wanted to do was understand the impact deprivation has on life expectancy, specifically in young people.
"I was surprised just how difficult it was to find the data I needed to complete this research and I've discovered that a study like this, focusing on deaths in young people under the age of 25 across Scotland, simply hasn't been undertaken before.
"The results of the research really couldn't paint a clearer message and underlines the massive inequality between rich and poor in this country."
In the wake of the findings, Aberlour has launched a new fundraising campaign, A Bad Start Shouldn't Mean a Bad End.
The charity is calling on the Scottish Government to set up a transitional fund that will help councils deliver early intervention services to help those in need, as well as providing the specialist help needed by families struggling with poverty and inequality.
In addition to this, it wants ministers to adopt a "child well-being approach" when setting the budget so public spending makes children's well-being a top priority.
Businesses are meanwhile urged to help by providing more flexible, secure, family-friendly employment.
Aberlour chief executive SallyAnn Kelly said: "This research makes for a really shocking read.
"We know that in order to break this cycle of deprivation we need to get to Scotland's young people early.
"We are currently supporting 7,500 vulnerable children and young people across Scotland but we know that there are thousands more that urgently need our help."
She spoke out as she launched the charity's new campaign, with support from MSPs from across the political spectrum.
Ms Kelly said: "Aberlour knows the real and proven difference that our services make to the lives of children and young people in Scotland's most deprived communities and we are asking the Scottish public to help us continue to deliver these vital services today.
"Looking ahead to the future, it's time for a conversation about how we end the unacceptable consequences of poverty in this country.
"We need a political response that meets the needs of vulnerable young people and matches the generosity and support of Scotland's people."
A Scottish Government spokeswoman said: "We recognise the damaging impact poverty can have on young lives, that is why we have set in statute our ambition to eradicate child poverty in Scotland.
"Our Tackling Child Poverty Delivery Plan sets out the concrete actions we will take to deliver progress.
"These include investing £22 million in a package of new employability support for parents, helping families to work and earn more, launching our new Best Start Grant and providing financial support to low-income families across the early years - backed by £21 million this year."
She added: "In 2018-19, we invested over £1.4 billion in support, which was targeted on low-incomes families.
"This will go further in future with the new Scottish Child Payment offering £10 a week per child to low-income families by the end of 2022.
"Scotland is the only part of the UK to set statutory income-based targets for reducing child poverty and we are doing in the face of continued UK Government welfare, which are set to reduce spending on social security in Scotland by £500 million a year."