While the country's economy has returned to the level it was at before the economic crisis hit, wage levels have not made the same progress.
Analysis to be published by the Scottish Government suggests average earnings have fallen back to 2005 levels.
It comes as the number of Scots in work reached a record high of 2.59 million earlier this year.
Training, Youth and Women's Employment Secretary Angela Constance said: "Despite continued improvements in Scotland's economic performance, too many households still struggle to meet their bills with wages eroded and the cost of living increasing."
Youth unemployment has fallen by 2.9% over the year, and is now level with the UK rate, while the number of women in employment in Scotland has reached a record level of 1.25 million - 36,000 more than a year ago.