Hospitals should sell e-cigarettes and remove smoking shelters from their grounds, health officials have said.
Permitting the use of vapes in designated hospital lounges and being able to purchase e-cigarettes from hospital shops, should be allowed, according to Public Health England.
Licencing e-cigarettes as medical quitting aids could be one way to get people to stop smoking, as it would allow GPs to prescribe the devices to patients.
In a PHE report, they estimated e-cigarettes could contributing to 20,000 people quitting smoking each year and they are significantly less harmful than smoking tobacco.
In a linked editorial, published in The Lancet, experts from PHE said: "Although not without risk, the overall risk of harm is estimated at less than 5% of that from smoking tobacco; the risk of cancer has been calculated to be less than 1%."
Martin Dockrell, tobacco control lead for PHE, said: "We are saying no smoking anywhere on the grounds [of hospitals], no smoking in the smoking shelter - that shelter becomes a vaping shelter.
"There are two parts to being a smoke-free hospital, one is not allowing smoking on the premises, the other is helping every smoker to quit."
Professor John Newton, director for health improvement at PHE, said: "Every minute someone is admitted to hospital from smoking, with around 79,000 deaths a year in England alone.
"Our new review reinforces the finding that vaping is a fraction of the risk of smoking, at least 95% less harmful, and of negligible risk to bystanders.
"Yet over half of smokers either falsely believe that vaping is as harmful as smoking or just don't know.