Alex Salmond said the party had recorded a strong performance
The SNP is on course for its best Westminster election performance in more than 30 years, according to leader Alex Salmond.
The party said it had secured decisive wins in seats like Dundee East, Perth and North Perthshire, Angus and Moray.
However, it failed to take its target seat in Dundee West and lost in Glasgow East, which John Mason had captured from Labour in a by-election in 2008.
Mr Salmond said the party had recorded a "strong performance".
He said the SNP's vote had increased in key seats across the country.
"Early results suggest the SNP is on course for our best result since the 1970s in a Westminster election," said Mr Salmond.
"The Lib Dems have failed in Scotland and are being pushed into third or even fourth place.
"The picture across the UK may be unclear, but it is clear the Tories have had a disastrous night as they have once again been decisively rejected across Scotland."
The SNP had set a target of winning 20 seats - although it has acknowledged that it is now unlikely to meet that target.
During the campaign Mr Salmond said a hung parliament, where no single party wins a Commons majority, would provide an "opportunity" for change.
A BBC/ITV/Sky exit poll has suggested the Conservatives could finish as the largest party, but 21 seats short of an overall majority.