Patients and visitors at St Thomas' Hospital are "resistant, sometimes to the point of aggression" when asked not to smoke, an NHS boss has complained.
Amanda Pritchard, chief executive of the Guy's and St Thomas' NHS Foundation Trust, used her report for next week's board meeting to announce plans to "reboot" the trust's anti-smoking campaign.
Guy's and St Thomas' banned smoking in summer 2015.
"Helpfully, King's College London has now designated its parts of the Guy's site as smoking free which will enable us to secure greater compliance," wrote Ms Pritchard.
"St Thomas' has been much more difficult to turn smoking free and patients and visitors are resistant, sometimes to the point of aggression, when they are asked not to smoke on site.
"Whilst we should remain intolerant of visitors smoking on site, it is clearly more difficult with patients.
"We will be putting new signage and posters up at St Thomas' which will be prominent and unavoidable and responsibility for enforcing the rules will pass to Essentia and the security team.
"We have taken advice from other organisations with experience of poor behaviour from users and will be offering training and support for the staff involved to deal with this behaviour."
This week Guy's and St Thomas' announced it was issuing body-worn cameras to security staff after a rise in the number of attacks on staff.