Former ministers have condemned the move, saying it would be wrong to spend millions on advertising when many health trusts are cutting jobs to balance their books.
The Department of Health has urged trusts to draw up local marketing plans to promote their services as part of its plans to offer patients a choice of hospitals. Future funding will depend on their success in attracting patients.
Some trusts have already recruited market research companies and are expected to link up with agencies before launching campaigns.
Frank Dobson, the former health secretary, has led the criticism. He has tabled Commons questions on the issue in an attempt to find out how much is being spent on ads.
John Spellar, another former minister, said he was "disappointed" that hospitals could spend money on "glossy advertising". He added: "Money should be spent at the sharp end, not on bureaucracy."
Liam Byrne, the junior health minister, said: "A small amount of advertising is in the interests of both patients and hospitals. We are developing guidelines to ensure communications are honest, accurate and appropriate."