Lib Dem leader Sir Menzies Campbell accepted it had been a "mixed bag" of results after his party's share of the vote fell a point from 2006 to 26%.
Sir Menzies says the results are a 'mixed bag'.
But he claimed "three-party politics is here to stay" after taking Hull Council in John Prescott's constituency.
The victory was a bright spot despite a net loss of 242 English councillors, mostly lost to the Conservatives.
But, he said: "Nationally the Lib Dems have won a higher vote share than in the last general election."
'Here to stay'
The BBC's projected share of the vote across Britain puts the Conservatives on 40% - one point up on 2006, with Labour on 27%, also one point up.
Despite some significant successes, the Lib Dems saw key southern councils like Bournemouth and Torbay fall to the Conservatives.
In Scotland, the Lib Dems won 16 seats - a net loss of one seat.
In Wales, the party kept six seats.
Sir Menzies told BBC Radio 4's Today programme that his party had proved it was a "permanent feature" on the British political landscape.
He said he would prefer his party's share of the vote to be higher than 26%, but added: "I've always said these were going to be tough elections for us.
"And to win Hull from Labour, not just John Prescott, but Alan Johnson's home territory, and to win Eastbourne, right in the heartland of the Conservatives - these are two very significant results, but I accept, it's a mixed bag."
Sir Menzies claimed that Labour had been "wiped out in the south", while the Conservatives "have failed to make any inroads into the northern cities".
"These results show that three-party politics is a permanent feature of the British political landscape," he said.