A taxpayers' campaign group said the cost was "obscene" and would be better spent on schools and teachers' pay.
The jobs were shown in a three-quarter page slot in the Guardian newspaper.
The Taxpayers' Alliance said the posts were a "massive waste" of taxpayers' money in tough economic times.
Mark Wallace, campaign director of the alliance, said: Who could possibly think, 'we've got nearly half a million to spend on education - let's spend it on Ofsted press officers'?
"It's obscene. Shocking. If the government's got half a million to spend on education it should go on schools or teachers' pay not PR men. OK maybe they need one or two press officers - but 12?
"We may be on the verge of the worse economic recession for years. These are hard times.
"There must be so many schools that are short of money, so many parents struggling to find money for uniforms and school trips and so on. What must they think?"
Ofsted issued a statement saying there was only one new post advertised. "All the rest are current posts that have been changed to reflect new communications demands such as our website, which can receive in excess of seven million hits a month," the statement said.
"Our recruitment is not about press and PR but about ensuring that the 50,000 reports we publish each year are accessible to parents, students and staff, so that schools, colleges, nurseries and other providers are properly and publicly held to account.
"The team has been recently restructured to better support Ofsted's work."
