The Thai Government has launched a campaign to encourage Buddhist monks to give up smoking.
The initiative comes after a new report identified smoking as the leading cause of death among monks in Thailand.
Smoking-related diseases have increased by nearly 90% in the last three years, according to statistics from the Monks' General Hospital - the only one in the country that just treats clerics.
Half the country's 300,000 monks are smokers, but earlier initiatives to get them to kick the habit have largely been ignored.
'Against moral values'
There is no religious edict banning monks from smoking, although alcohol is off-limits.
The BBC's correspondent in Bangkok, Simon Ingram, says the sight of a saffron-robed monk puffing casually on a cigarette is not an unusual one in Thailand.
Even revered senior clerics can sometimes be seen smoking while dispensing religious advice on television.
But Warabhorn Bhumisawasdi, Director General of the Institute for Tobacco Consumption Control, says the practice goes against the moral values of Buddhism, as monks are the spiritual leaders of lay people.
Teams of doctors and health officials will talk to monks at temples across the nation to warn them of the dangers of smoking, Ms Warabhorn said.
In addition to the health campaign, smoking will be banned in Thai temples.
"Temples are the places where many monks and Buddhists meet for religious ceremonies," and therefore passive smoking there should be prevented, said health minister Sudaray Keyuraphan.
Monks are required to lead a luxury-free life of celibacy, and must live on alms donated by the public.
However, many temples have plenty of money, and the monks can lead a comfortable life.