Labour, the Scottish National Party and the Tories each look set to return two MEPs and the Liberal Democrats one. The full results will be announced about noon on Monday. This is how the parties have reacted so far:
Labour: Scottish Secretary Alistair Darling
Elected MEPs will sit at the European Parliament in Strasbourg
"What is encouraging about these results from my point of view - despite the fact that this is not a good night for the government - is that in the fundamentals, things that matter to people like the economy, like jobs, public services, people still think we are going in the right direction but are saying we need to do more.
"At this time, given the unpopularity of the government, frankly the Tories should have done better and for the Nationalists to have gone backwards is a truly miserable result for them.
"In this country there is a strong strain of scepticism, but in relation to Europe, those of us who believe that Scotland's future does lie in being fully engaged in Europe, we must ensure that we get our arguments fully across.
"There are lessons to be learned for everybody, including the government, but I am confident that if we get things right, if we can step up our game, we will win the next general election."
SNP: Party leader John Swinney
"Our performance is broadly in line with what we achieved in the regional result for the Scottish Parliament last year and what we are in the process of doing is building the SNP from the position we achieved last year.
"The results will see the SNP have two seats in the European Parliament, they see us retaining second place in Scottish politics and they see us closing the gap on the Labour Party in terms of the result last year.
"There was a sizeable proportion of the vote for fringe parties and the message we have tried to get across to people in Scotland is there are many, many ways you can kick the Labour Party if you're dissatisfied with them.
"But, if you want to change the political direction of Scotland, you have to vote for the principal opposition party that is best placed to beat the Labour Party."
Conservatives: Party leader David McLetchie
"I am delighted with our result in Scotland - winning two seats out of seven, which is an improvement on two out of eight.
"Looking ahead we won seven out of 14 Scottish constituencies and came second in another 11, and we have improved our share of the vote on the Scottish
"We are now breathing down the neck of the SNP - roll on the general election."
Lib Dems: Party leader Jim Wallace
"This is an excellent result for the Scottish Liberal Democrats and for Elspeth Attwooll.
"The Scottish Liberal Democrats have increased their share of the vote compared with the last European elections.
"We know that it's through hard work and solid campaigning that we make progress and these elections bear that out."
Greens: Parliamentary leader Robin Harper
"The Greens, who were people's second choice in the Scottish elections, have now become people's first choice.
"The core green vote in Scotland is solid as a rock, which bodes very well for forthcoming Westminster and Scottish elections. We now have our sights on Labour in key seats.
"We hail the results across Europe that sees almost 40 Greens returned to the European Parliament, including Green MEPs Caroline Lucas and Jean Lambert from the UK - we couldn't send a Green from Scotland to join them this time, but with this steady increase in Green votes our time will come."
SSP: Leader Tommy Sheridan
"It represents progress for the SSP but this may have been an election too far at this stage."