More Scots than ever have described themselves as having no religion, according to new research.
The Scottish Attitudes Survey, compiled by the independent research body ScotCen, found 58% of respondents said they had no religion at all.
When the survey was carried out in 1999, the figure was 40%.
Among major denominations, the Church of Scotland has seen the sharpest decline, with just 18% saying the belong to the Kirk.
The Church of Scotland figure for 1999 was 35%.
ScotCen researcher Ian Montagu said: "The decline in religious identity in Scotland has been most keenly felt by the Kirk as fewer and fewer people choose to describe themselves as Church of Scotland by default.
"As each generation coming through is consistently less religious than the last, it is hard to imagine this trend coming to a halt in the near future."
He added: "However, if the Kirk is able to push through liberalising measures such as allowing ministers to oversee same-sex marriage ceremonies, it is possible that its appeal may broaden somewhat to younger, more socially liberal Scots."
The Reverend Norman Smith, the convener of the Church of Scotland's Mission and Discipleship Council, said: "This survey contains no surprises for us a Church, however for us it is only part of the story.
"Other surveys such as that reported recently in the Daily Telegraph show that Christianity continues to have an impact on people's lives.
"The challenge for us then as Church is to find ways that connect people's everyday life to faith. We recognise the Church needs to develop new ways of communicating a faith that we believe is still relevant to life in the 21st century."
The survey found the proportion of Roman Catholics (10%), other Christian affiliations (11%) and those of non-Christian faiths (2%) have remained stable within the Scottish population.
The Scottish Social Attitudes Survey was based on a sample of 1,237 people interviewed between July 2016 and December 2016.