The X-Factor sponsor received more than three times as many complaints per 1,000 customers as its closest rival for its phone services and twice as many regarding its broadband packages.
However, the number of complaints levelled against it fell by around 50 per cent compared to the last quarter of 2010.
Virgin Media received the lowest number of complaints for both phone and broadband services, with BT and Sky roughly level.
The survey comes after TalkTalk was fined a record £3m by Ofcom for incorrectly billing tens of thousands of consumers for services they had not received during the integration of Tiscali.
A TalkTalk spokesman called the results “encouraging” but admitted there is still much work to be done.
Meanwhile network operator Three topped the complaints list for mobile services, attracting a third more complaints than Orange, T-Mobile and Vodafone and three times more than best performer O2.
Ernest Doku, technology expert at uSwitch.com, said: “Since Ofcom began compiling the data nearly a year ago, TalkTalk Group has stood out as the worst performer in both landline and fixed broadband services. But while there is still more to be done, TalkTalk is clearly pulling its socks up. In the second quarter of 2011 they received substantially fewer complaints than in the first quarter. These are positive steps.”