Local education authorities are being urged to use sniffer dogs to stop drugs being brought into schools.
Dogs can detect drugs up to 72 hours after use
Criminologists evaluated a pilot scheme at six Buckinghamshire secondary schools and found the dogs effective.
The John Grieve Centre for Policing and Community Safety made an independent study of the programme and recommended that it should be extended.
Researchers warned procedures needed to be robust so that children did not play truant to avoid being caught.
Two kinds of sniffer dog were used in the schools.
A proactive dog, typically a spaniel, searched buildings and classrooms, while a passive dog, a Labrador, was stationed inside school gates to detect whether pupils were carrying drugs, or had come into contact with them.
Professor Allyson MacVean, who led the study, said the animals should be part of every school's anti-drugs strategy.
But she said personal searches might be more effective if they were conducted at random while lessons were in progress.
If pupils thought they would be checked as they came in, they would play truant.
Children could also warn their peers of searches by mobile phone.
A study by Buckinghamshire Chilterns University College, found most pupils (82%), parents (98%) and staff (92%) were in favour of the use of dogs.
Discipline and counselling
The report said those caught in possession should be subject to both a "robust disciplinary procedure" and rehabilitation and counselling.
A National Centre for Social Research study of 225 English schools in 2000 found more than one third of pupils had been offered at least one drug, the most common being cannabis.
For the Buckinghamshire Chilterns study, 260 questionnaires were returned - 100 from pupils, 88 from parents and 72 from staff.
Of the children, 11% said they had been offered drugs in school, while 12% had tried them.
Last year, sniffer dogs started working on some school buses in South Yorkshire, carrying out random checks.
Random drug tests on pupils have also been used at the Abbey School in Faversham, Kent, since January.