Also, however, it was one of nine constituencies in the Lothians electoral region, which elected seven additional members, in addition to nine constituency MSPs, to produce a form of proportional representation for the region as a whole.

[1] The Holyrood constituency was one of two covering the Midlothian council area.

The other constituency, Tweeddale, Ettrick and Lauderdale, covered a western portion of the Midlothian council area, and straddles its boundary with the Scottish Borders council area.

Tweeddale, Ettrick and Lauderdale was within the South of Scotland electoral region.

Following their First Periodic review of constituencies to the Scottish Parliament, the Boundary Commission for Scotland recommended extending the current Midlothian constituency into a newly formed seat of Midlothian North and Musselburgh with the western boundary to the south of Auchendinny.