With the NHS now giving patients more choice about where they are treated, Circle is targeting potential patients through the campaign. The first ads will appear in September and will run in press, outdoor and online.
Circle calls itself part of the "new wave" of healthcare providers. It has just opened its first hospital, in Bath, and plans to build 30 more around the UK.
The hospitals serve NHS and private patients. Bath offers treatments including orthopaedic and ear, nose and throat surgery, but Circle plans to offer a wider range of services including bariatric weight-loss operations and cosmetic surgery.
The first hospital was designed by Sir Norman Foster, the architect behind the new Wembley Stadium and the Millennium Bridge.
Christina Lineen, head of communications at Circle, said: "Our hospitals and the quality of healthcare we give all our patients will be second to none. We looked for a creative agency that would create communications like no other in the healthcare sector, and we are delighted to have London Advertising as our partner to achieve this."