Hertfordshire South West is a rather curiously shaped constituency running from South Oxhey, Eastbury and Rickmansworth in the south to Tring, Aldbury and Long Marston in the north. Some 22 miles long it is, in places, just 3 miles wide.

Image produced from the Ordnance Survey Election-Map service.
Image reproduced with permission of Ordnance Survey and Ordnance Survey of Northern Ireland.

However, the A41 means that the journey time from one end of the constituency to the other is quite quick.

The constituency has been getting longer and thinner after each of the recent boundary changes. Prior to 1983, in addition to the likes of Rickmansworth, Chorleywood, Croxley Green and Moor Park, it also had Oxhey and Bushey. In 1983, Bushey was lost and Berkhamsted was gained. In 1997, Oxhey, Carpenters Park and Kings Langley all left the constituency but Tring was transferred from Hertfordshire West (renamed Hemel Hempstead).

Two district authorities cover the constituency. Three Rivers (covering 60% of the population) includes Rickmansworth, Chorleywood, Croxley Green, Moor Park and Eastbury, South Oxhey and Sarratt. The northern part of the constituency (Tring, Berkhamsted, Bovingdon, Chipperfield, Flaunden and various other villages) fall within the boundaries of Dacorum Brough Council.