David Cameron, the UK's new prime minister, had always said Mr Lansley, shadow secretary of state since 2003, would be in charge of health in a Conservative government.
It is as yet unclear whether the Lib Dem health spokesman Norman Lamb will be offered a role in the cabinet.
Former health secretary Andy Burnham will leave his post after just under a year at the DoH and all of Labour's other health ministers lost their seats in the election.
In a recent pre-election debate, Mr Lansley was criticised by Mr Lamb for accepting £21,000 in donations from the chairman of Care UK, John Nash. The Conservative party say the money was donated by Mr Nash's wife, a regular party donor.
The Conservatives and Lib Dems agree on the need to slash bureaucracy, admin and management costs throughout the NHS.
But they disagree on the options available to fund adult social care in the future. Talks between the three parties broke down earlier this year because Mr Lansley refuses to consider a compulsory levy.
The Tories also plan to ‘scrap all politically motivated targets' while the Lib Dem manifesto called for a patient contract to guarantee waiting times would not be broken.
Mr Lansley has been a key figure for the Tories as the NHS became a priority in their election campaign.
He is expected to rename the DoH to reflect the Conservative's commitment to public health and preventative medicine.
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