Population projections have forecast Dumfries and Galloway will have the highest percentage of people over 65 in Scotland in 20 years time.
Office of National Statistics figures show more than a third of its residents (34.6%) will be pensioners by 2031.
It is forecast that nearly a quarter of the UK population will be over 65 by that time, a rise of 5%.
Many other parts of Scotland will also see a significant rise in that section of the population.
Dumfries and Galloway is forecast to be the local authority area with the largest percentage of people at the current state pension age.
The Shetland Isles is on course for a 14.7% increase from its current rate of 17.9% - reaching 32.6%.
Other areas with an increasingly "grey" population include Eilean Siar (32.7%), East Dunbartonshire (32.1%) and Argyll and Bute (31.8%).
UK Pensions Minister Steve Webb said the figures showed the need to consider phasing out the default retirement age.