Secondary school pupils across England and Wales could face random drug testing after a pilot scheme was found to help children resist peer pressure.
Head teachers will not be obliged to introduce random testing, which is carried out using mouth swabs, but the government has said it would support schools which do.
A pilot scheme is to be held across schools in Kent this autumn, led by the man who first introduced random drugs testing when he was head of the Abbey School in Faversham.
Peter Walker claims that since the scheme was introduced, both exam results and pupil behaviour have improved at the 960-pupil school, whose catchment area includes the second most deprived council ward in the country.
He also insisted the possibility of being tested helped pupils withstand peer pressure and say no when they were offered drugs.
"The biggest reason for taking drugs is peer group pressure. It looks like we may well have found a way for children to have a viable way of saying no to their peer group," he said.
Last year, 41 per cent of pupils at the Abbey school, a specialist school for business and enterprise, achieved five GCSEs of grade C or above, compared to a previous high of 30 per cent.
"We had our best set of exam results in the school's history. There's less disruption in the classroom, less incidents in the playground or on the way to school," Mr Walker said.
Last year about 600 tests were carried out on pupils aged between 11 and 18, for drugs such as cannabis cocaine and heroin. Just one pupil tested positive, for cannabis.
The children were not forced to take part in the random testing but if they refused their parents were called in, and Mr Walker said 86 per cent of parents agreed to the scheme.
The former head teacher is currently drawing up guidance for schools who may wish to adopt drugs testing, subject to the success of the Kent pilot scheme, although government officials insisted local parents would be fully involved in any decisions.
Education secretary Alan Johnson praised Mr Walker's commitment to the issue as "impressive", adding: "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."