1983–1997 • The District of South Bedfordshire wards of Beaudesert, Brooklands, Dunstable Central, Eaton Bray, Heath and Reach, Hockliffe, Houghton Central, Houghton East, Houghton South, Icknield, Kensworth, Linslade, Northfields, Plantation, Priory, Southcott, Stanbridge, Studham, Totternhoe, and Watling; and • The District of Mid Bedfordshire wards of Aspley, Cranfield, Marston, and Woburn.
The constituency was formed largely from the bulk of the abolished seat of South Bedfordshire, including Dunstable, Houghton Regis, Leighton Buzzard and Linslade. It was extended northwards to include south-western part of Mid Bedfordshire. 1997–2010 • The District of South Bedfordshire wards of Beaudesert, Brooklands, Dunstable Central, Eaton Bray, Heath and Reach, Hockliffe, Houghton Central, Houghton East, Houghton South, Icknield, Kensworth, Linslade, Northfields, Plantation, Priory, Southcott, Stanbridge, Studham, Totternhoe, and Watling.
Northern areas (comprising the District of Mid Bedfordshire wards) transferred back to Mid Bedfordshire.
2010–2024 • The Central Bedfordshire unitary authority wards of All Saints, Chiltern, Dunstable Central, Eaton Bray, Grovebury, Heath and Reach, Houghton Hall, Icknield, Kensworth and Totternhoe, Linslade, Manshead, Northfields, Parkside, Planets, Plantation, Southcott, Stanbridge, Tithe Farm, and Watling.
Local authority wards revised, but no changes to boundaries. == Members of Parliament ==