With the theme "Democratic governance against corruption", the summit hopes to launch concrete actions to fight this longstanding Latin American problem.
As if to prove the urgency of the question, host country Peru's president Pedro Pablo Kuczynski resigned just a few weeks ago to avoid impeachment over graft charges.
But corruption is a difficult crime to fight and has polarised the region, Antonio Sampaio, a researcher at the International Institute for Strategic Studies in London.
However, he believes it would be embarrassing if leaders cannot agree on a statement to strongly condemn the problem.
"We have to analyse very closely what comes out of these meetings," he told RFI. "To see if there is some international agreement on cooperation and tools to fight corruption, because that's the aim of the summit. If something really weak comes out of it, the summit will have been a failure because it is a topic that is easy to agree on. Corruption has to be rooted out."
Sampaio also says that one of the ways to improve the international fight against corruption is to increase cooperation between investigative agencies in different countries. And adopting a strong regional language against corruption that leads to practical implications could act as a deterrent.
However, other experts like the Economist Intelligence Unit's Giancarlo Morelli are not sure much will be achieved during the meeting.
"The sad part is that many of the presidents are going to leave [office]," he points out. "We have elections in Brazil, Paraguay, Costa Rica, Mexico, Colombia, and so you can't have strong agreements because their mandates are about to finish. Discussions might be not very strong. You'll condemn corruption, you'll talk about how to deal with corruption but there won't be strong agreements in the region."
Another major issue to be discussed is the political and economic crisis in Venezuela.
A presidential election, usually held in December, is coming up in May and the decision to bring it forward has been seen as an attempt to throw the opposition coalition into disarray.
Ahead of the summit, the Lima Group of 17 countries, which was formed to tackle the crisis in Venezuela, has said it will not recognise the results. The US has also said it would consider imposing further sanctions against Caracas if Maduro goes ahead with the vote.
According to Eduardo Rios, at the Observatoire Politique pour L'Amérique Latine in Paris, the only thing that can be done during the summit is to increase pressure on Venezuela.
"Maduro is in a situation in which he needs to rebuild the economy and the only way to do that is to increase the amount of commercial deals that he does with other countries in the region," Rios says. "So, if he doesn't have diplomatic support it means his path to growing the economy again is closed.
"So international pressure is important for the future, but it's not the only thing that will cause Maduro's fall. Internal political pressure is also needed."
On 10 April Maduro confirmed he would not attend the event, calling it "a waste of time".
Tensions with US
Also absent from the summit is US President Donald Trump, who cancelled the trip at the ast minute in order to deal with the crisis in Syria.
This is the first time a US head of state will not be present at the Summit of the Americas, which was initiated by then-president Bill Clinton in 1994.
Vice-president Mike Pence and senior advisers Ivanka Trump and Jared Kushner are attending in Donald Trump's place.
His absence was not well received by some Latin American countries, even if administration officials insisted this was not a snub or sign of disinterest in the region.
"The relationship between the US and Latin America has been, since the Obama-era, very bland," says Morelli. "With Trump, relations have been less harmonious and more confrontational, obviously driven by his America-first policy, but it's not exactly a change of policy. For Mexico and Cuba is different, but not for the region in general."
For Carlos Malamud, at the Elcano Royal Institute in Spain, however, the mood in Lima is very different to that at the last summit in 2015, which was marked by US-Cuba reconciliation.
"The relationship between Latin America and the US changed from the Obama administration to the Trump Administration, which is tougher with Venezuela and has changed most aspects of the Cuban policy," he says. "You also have a problem that did not exist before, which is the confrontation between the US and Mexico, the wall, the renegotiation of the Nafta [North Ameraca Free Trade] agreement, so the mood of the summit is absolutely different," says Malamud.
The Summit of the Americas will finish on 14 April.