Random drug testing could be introduced in all secondary schools after ministers backed a pilot scheme run by Kent council.
The Abbey school, in Faversham, was the first state school in the UK to bring in drug tests last year. Peter Walker, former head, said it helped to improve results.
He said: "We had our best set of exam results in the school's history.
There is less disruption in the classroom and fewer incidents in the playground and on the way to school. Children feel they are far better protected."
From September, all 103 Kent secondaries will be invited to join the scheme, in which mouth swabs are used to test for drugs such as cannabis, cocaine and heroin.
The Department for Education and Skills is funding the scheme and has commissioned research to establish whether there is a direct link between random testing and behaviour, attendance and academic achievement.
Ministers want the scheme introduced in all secondaries, but a DfES spokesman said the tests would not be mandatory.
Last year, 600 random tests were carried out on pupils aged between 11 and 18. Of the Abbey's 960 pupils, 86 per cent consented to the tests. Only one child tested positive, for cannabis. The pupil received counselling before leaving the school with seven GCSEs.
Mr Walker was appointed as the Government's ambassador for random drug testing when he retired as head two months ago. He is producing guidelines for schools and has met US drug tsar John Walters.
Mr Walker said: "It is not about catching people out - it is about helping people get off drugs. It is about time all schools accepted there is this problem we need to address. Anybody who says they don't have a drug problem in their school is not telling the truth."
A DfES spokesman said: "The decision to adopt this approach will be one for heads in consultation with parents. This is about providing schools who want to look at this approach with the best possible information and guidance, rather than forcing them to do it."
Alan Johnson, Education Secretary, said: "Mr Walker's drive and commitment are impressive. A key factor was peer pressure by the kids against taking drugs. I am determined schools should have all the support they need to tackle this issue."
Chris Keates, general secretary of NASUWT, said the union supported random drug testing and that she hoped the Kent scheme would become national.
She said: "A study in 2005 by the Centre for Policing and Community Safety showed that random testing was a successful strategy and commanded wide support from parents, pupils and teachers."
But Martin Ward, deputy general secretary of the Association of School and College Leaders, said many heads would be reluctant to adopt it.