The parliamentary constituency of Ross, Skye and Lochaber is the worst area in the UK for broadband, new figures show.
A total of 65.6% of connections in the rural constituency were below the UK government's proposed minimum standard of 10 megabits per second (Mb/s).
Scotland had eight of the 20 worst performing areas, according to analysis by the British Infrastructure Group of MPs.
It was closely followed by Wales with seven.
MPs' analysis of download speed data recorded by Ofcom in 2016 found Scotland had the four worst performing parliamentary constituencies in the UK.
More than 60% of connections in three other Scottish constituencies - Na h-Eileanan an Iar, Argyll and Bute and Orkney and Shetland - failed to reach download speeds of 10 Mb/s.
Kingston upon Hull East was the worst constituency in England for download speeds, with 56.8% of connections failing to hit the government's proposed universal service obligation.
A Scottish Government spokeswoman said: "We are committed to delivering 100% superfast broadband access across Scotland by 2021.
"This is the most ambitious commitment in the UK - focusing on delivery of speeds over 30mbps - whilst there is still no clarity from the UK government on how they intend to implement the proposed Universal Service Obligation for broadband - which will deliver just 10mbps.
"Alongside our partners, we have invested over £410m in the Digital Scotland Superfast Broadband programme and are on track to deliver fibre broadband access to at least 95% of premises across Scotland by end 2017, and that thanks to the programme around 780,000 premises have been connected to fibre."
10 worst constituencies for download speeds
- Ross, Skye and Lochaber, Scotland 65.6%
- Na h-Eileanan an Iar, Scotland 63.7%
- Argyll and Bute, Scotland 61.7%
- Orkney and Shetland, Scotland 61.7%
- Carmarthen East and Dinefwr, Wales 58.2%
- Montgomeryshire, Wales 58%
- Kingston upon Hull East, Yorkshire and the Humber 56.8%
- Ceredigion, Wales 55.1%
- North Herefordshire, West Midlands 54.9%
- Caithness, Sutherland and Easter Ross, Scotland 52.2%
Percentage of connections below 10 Mb/s