Scottish independence: Second TV clash for Salmond and Darling
They are expected to clash on issues such as currency, the NHS and North Sea oil and gas estimates.
It is the second time the two leaders have met face-to-face for a television referendum debate.
It will be screened on BBC One Scotland, and across the rest of the UK on BBC Two, from 20:30 BST.
Scotland will go to the polls in a referendum on 18 September, answering the "Yes/No" question: "Should Scotland be an independent country?"
The broadcast will be split up into four sections....
SECTION ONE: Opening statements - Alex Salmond will go first, Alistair Darling second. (Mr Salmond won the coin toss and elected to go first).
SECTION TWO: The issues- The two men will debate four topics titled;
- Scotland at Home
- Scotland in the World
- What Happens after the Vote
(Each will be introduced with a question from the audience.)
SECTION THREE: Cross-examination - Alistair Darling will go first, Alex Salmond second. (Mr Darling won the coin toss and elected to go first).
SECTION FOUR: Closing statements - Alex Salmond will go first, Alistair Darling second. (Mr Darling opted to go second).
The first leaders' debate aired on STV on 5 August, with both sides claiming victory.
Monday's 90-minute event will be staged at Kelvingrove Art Gallery and Museum in Glasgow in front of an audience of 200 people selected by polling and research consultancy ComRes.
The debate is being presented by Glenn Campbell and will begin with opening statements from both leaders.
At the venue - Laura Pettigrew, BBC News online reporter
In the stuffed animal hall at Kelvingrove Museum and Art Gallery, where a Spitfire hangs overhead, there's an eerie calm.
Gone are the laughing toddlers or tourists with their cameras normally found here on a Monday afternoon. Instead a lone cleaner with a bin bag wanders through.
The museum is closed to the public for one day only. It may be unusually quiet in this part but the main entrance hall is a hub of activity. It has been transformed for tonight's referendum debate.
A huge platform has been erected and tiered seating installed. Big pink screens form the backdrop for the televised face-to-face, with three illuminated lecterns for Mr Salmond, Mr Darling and presenter Glenn Campbell.
Production and technical stuff are putting the final touches to the set. "We need a mat over here" says the floor manager. "We'll be bringing the audience in this way."
Outside the world's media is gathered. Satellite trucks line the road and journalists prepare viewers for a "head-to-head", "clash" and "showdown".
At the door, a few eager museum-goers are turned away. They're not impressed. "Seems like a lot of fuss to me", says one. "I thought we might get to be on TV," says another.
BBC Scotland said Mr Salmond had won a coin toss and had chosen to go first with his opening statement.
There will then be four issue sections devoted to the economy, Scotland at home, and in the world, and what happens after the vote. Each of these will begin with a question from an audience member.
The two men will then cross examine each other and the debate will be rounded off with closing statements.
Watch and listen
TELEVISION:Watch and read about the build-up, ahead of it all starting at 20:30 and running until 22:00. For Scotland viewers, you can watch the broadcast on BBC One Scotland. For viewers in England, Wales and Northern Ireland you can watch on BBC Two. The debate will also be shown on the BBC News Channel and BBC World News. If you miss it live, you can tune in to BBC One between midnight and 01:30 to watch again. And of course the programme will be made available on the BBC iPlayer.
For post-debate analysis, BBC Two Scotland has an extended Scotland 2014 programme, hosted by Sarah Smith, which will start at 22:00 and run to 22:40.
RADIO: The build up on BBC Radio Scotland MW and digital begins at 20:00. You can then listen to the debate live between 20:30 to 22:00. After that there will be a special phone-in programme to take your views, between 22:05 to 23:00. That will be followed by Referendum Tonight, hosted by Graham Stewart. Radio Nan Gaidheal will also broadcast the debate.
ONLINE: There will be live streams of the debate on the BBC News website and across non-BBC media outlets in Scotland and elsewhere in the UK.
Both sides in the referendum campaign insisted their man came out on top when the two leaders met for their first debate earlier this month.
Key moments of the debate included Mr Darling being asked 21 times if he agreed with David Cameron that it was possible for Scotland to be a "successful independent country".
Mr Darling's repeated questioning of Alex Salmond's currency plans for an independent Scotland elicited the biggest response on social media, with more than 2,000 tweets during that segment of the debate.
How did it all begin?
Alex Salmond and Alistair Darling have each been in the party political arena for more than 30 years. Mr Darling reached high office when he served as Chancellor of the Exchequer in Gordon Brown's Labour government. That is a quite some distance from where he started, as a passionate left-wing student activist.
Mr Salmond, born in 1954 in Linlithgow, graduated from St Andrews University and became an economist, working for the Scottish Office and the Royal Bank of Scotland. But a career in politics soon called and he is now leader of the SNP (a post he has held twice), and is Scotland's longest serving first minister.