Hundreds of legislators from all 28 member states will converge on the Scottish capital for discussions on a range of security matters.
Non-member countries - including Korea, Pakistan, Afghanistan and Russia - will also be present.
British Foreign Secretary David Miliband is due to address the 55th annual assembly, hosted by the UK Government, when it closes on Tuesday.
The Nato assembly will focus on six themes before drawing up resolutions.
These will include reinforcing nuclear non-proliferation and "moving beyond" the economic crisis.
Today's opening session will be addressed by assembly president John Tanner and Bruce George MP, leader of the UK delegation. Committees are scheduled for Saturday.
Protests are expected over the weekend, including a rally organised by the "Nato Welcoming Committee".
A mass demo is being called to coincide with the first day of the assembly, and other "target" firms, linked to Nato, have been posted on protest websites.
Flyers have appeared around the city calling on people to "crash their party".
A separate event today at the Scottish Parliament has been organised by SNP MSP Bill Kidd as a "counterpoint" to the Nato assembly.
The backbencher said: "It is my intention to reiterate the commitment of the Scottish Parliament, the Scottish Government and the Scottish National Party to nuclear non-proliferation and disarmament."
Why are you making commenting on The Herald only available to subscribers?
It should have been a safe space for informed debate, somewhere for readers to discuss issues around the biggest stories of the day, but all too often the below the line comments on most websites have become bogged down by off-topic discussions and abuse.
heraldscotland.com is tackling this problem by allowing only subscribers to comment.
We are doing this to improve the experience for our loyal readers and we believe it will reduce the ability of trolls and troublemakers, who occasionally find their way onto our site, to abuse our journalists and readers. We also hope it will help the comments section fulfil its promise as a part of Scotland's conversation with itself.
We are lucky at The Herald. We are read by an informed, educated readership who can add their knowledge and insights to our stories.
That is invaluable.
We are making the subscriber-only change to support our valued readers, who tell us they don't want the site cluttered up with irrelevant comments, untruths and abuse.
In the past, the journalist’s job was to collect and distribute information to the audience. Technology means that readers can shape a discussion. We look forward to hearing from you on heraldscotland.com
Comments & Moderation
Readers’ comments: You are personally liable for the content of any comments you upload to this website, so please act responsibly. We do not pre-moderate or monitor readers’ comments appearing on our websites, but we do post-moderate in response to complaints we receive or otherwise when a potential problem comes to our attention. You can make a complaint by using the ‘report this post’ link . We may then apply our discretion under the user terms to amend or delete comments.
Post moderation is undertaken full-time 9am-6pm on weekdays, and on a part-time basis outwith those hours.
Read the rules hereComments are closed on this article