A union has urged NHS Grampian not to impose a smoking ban on its hospital sites, BBC Scotland can reveal.
NHS Grampian took a step towards banning smoking in its grounds with the recent launch of a consultation.
The local Unison branch said there were concerns about fairness to staff, patients and visitors.
Unison also said there were fears about people trying to evade such a ban, and the potential for this leading to a risk of fire.
Unison said it issued a survey to its members and other staff, and that the response showed that 87% of those who took part had concerns about the proposed total ban.
More than half who took part were said to be non-smokers.
Sandra Dee Masson, chair of the Unison branch, said: "We all know that even though people are only meant to smoke in the designated smoking shelters on NHS sites at the moment, a lot of smokers are still smoking in other, more dangerous places like loading bays outside the entrances to hospitals and in toilets.
"Unison decided to consult its members on the proposed total ban and the message coming back from them is clear - it's ridiculous to try and impose a total ban when the current arrangements aren't working properly.
"Staff are also concerned about the effect this will have on vulnerable patients."
She added: "We are therefore asking NHS Grampian to reconsider the total ban and instead beef up enforcement of the current arrangements and continue to improve the support available to staff, patients and visitors who wish to give up smoking.
"We think the current drive to reduce smoking on NHS Grampian sites will be undermined if an unenforceable total ban is introduced."
NHS Grampian launched its consultation earlier this year.
The consultation on extending the ban to all grounds includes staff, patients, visitors and local community groups.
Tobacco control co-ordinator Derek Petrie said at the time: "NHS Grampian's aim is to improve the health of everyone in the north east.
"NHS Grampian has a responsibility under British and European employment legislation to maintain a safe and healthy working environment.
"Our consultation will welcome suggestions on how NHS Grampian can raise awareness of the revised tobacco policy, any potential problems in implementing the smoking ban, and which measures we can use to help smokers follow the policy."
Smoking has already been prohibited inside hospital buildings.