He said if he is re-elected in the next general election he will maintain the so-called "triple lock" for the duration of the next parliament, ensuring that pensions rise by at least 2.5 percent a year until 2020.
In an interview with the Sunday Times, Cameron said it was "fair" to prioritise pensions even at a time when benefits for younger people were being slashed. Cameron's pledge to raise state pension is described by media as move to attract elderly voters.
Cameron: Pensions rise by at least 2.5 percent a year until 2020
Meanwhile, Cameron also hinted to cut taxes for all workers. "I want to see an economy that is performing strongly enough where we can afford to allow people to keep more of their own money to spend as they choose," he said.
"We're cutting taxes this year, achieving the 10,000 pounds personal allowance which, when taken with out other changes, make people 705 pounds a year better off."
A new poll commissioned by former Conservative chairman Michael Ashcroft published on Sunday said the Conservetative Party had lost the support of a third of those who voted for it in the last election held in 2010.
Some 37 percent people who voted Conservative Party in 2010 said that they would not do so tomorrow.
The other major political parties, the Lib Dems and Labour, have both supported the pensions "triple lock" but have made no commitment about whether they would keep it after the next election.
The "triple lock" system which was agreed in 2010 meant the basic state pension rose by 5.2 percent in 2012, or 5.30 pounds a week, the largest cash rise ever seen.