Hospitals in Galway, Waterford, Meath and Louth are introducing a smoke-free campus policy to mark National No Smoking Day.
The initiative has already proved highly successful in hospitals in Dublin and Cork.
The Health Service Executive has set a target of introducing a smoke-free campus policy to all health campuses by 2015.
About 1,650 people in Ireland die from lung cancer every year. Smoking cigarettes is by far the biggest risk factor and responsible for 90% of cases.
The HSE has developed a Quit Campaign to provide supports for patients during their hospital stay and help them to manage their addiction.
