Scotland's population is expected to drop below five million by 2017 and not 2009 as experts had predicted.
Scotland has the fastest falling population in Europe
The Registrar General Duncan Macniven said his revised figure took into account an increase in the birth rate and a rise in migrant workers.
However, he said deaths still exceeded births in Scotland so the population would continue to decline.
First Minister Jack McConnell recently launched the Fresh Talent initiative to attract people to live in Scotland.
Mr Macniven said: "Our last projections, based on 2002 estimates, suggested that the population would fall below five million in 2009.
"The latest figures take account of two recent factors - an increase in the number of births and in the number of people migrating to Scotland, mostly from the rest of the UK.
"But deaths still exceed births so the slow decline in Scotland's population is set to continue."
The figures released by the Registrar General suggest:
- The total population of Scotland is projected to fall from 5.06 million to below 4.9 million in 2028
- The number of people of working age is projected to fall by 8.5% from 3.16 million in 2003 to 2.89 million in 2028
- The number of people of pensionable age is projected to rise by more than 27% to more than 1.2 million in 2028
- The population of men aged 65 and over is projected to increase by 60% by 2028 and 40% of the female population
- The mean age of the population is projected to rise from the current figure of 40 to 45 by 2028.
The Fresh Talent initiative aims to bring 8,000 new people to the country each year.
Scotland has the fastest falling population anywhere in Europe.
Mr McConnell has advertised Scotland as "the best small country in the world" and says he believes the Fresh Talent programme will reverse population decline.