Victor Krastev, the headteacher at the Hristo Botev school in Bulgaria's northern city of Vratsa, brought in the obligatory alcohol check for all the teachers at his school after complaints from students that they were turning up smelling of beer and a local homemade spirit called rakia.
Mr Krastev said: "At first the teachers thought I was joking, but they soon got used to the test, and it works perfectly.
"Now they are all as sober as babies and we have seen a 15 per cent improvement in grades."
He said he planned to pass on his methods to other heads with similar staff problems.
So could breath tests be coming to schools in Britain next?
John Bangs, the head of education at the National Union of Teachers, said that teachers would oppose such a move - not out of fear, but because it would "give the impression that teaching is a drunken profession, which could not be further from the truth".
However, a spokeswoman for the Department for Education and Skills said that it would be a matter for local authorities and employers to decide.
You have been warned.