The host of the summit, the British Prime Minister Tony Blair, has arrived at Gleneagles, fresh back from Singapore where he supported London’s bid to host the 2012 Olympics.
He is welcoming the leaders of Germany, Canada, the US, France, Italy, Japan and Russia.
Poverty in Africa and climate change are the main topics on the agenda. Observers say while debate is likely to be intense it will probably end up inconclusive.
Those outside the summit venue accuse the group of the world’s richest nations of failing the poor, and they say they are determined to disrupt the meeting.
Tight security has been put in place around Gleneagles, with about 10,000 police from across the UK brought in to keep the demonstrators at arm’s length.