In January, CBBC Newsround Online reported that one school in the West Midlands was carrying out random checks on its pupils using the specially-trained animals.
Now seven schools in Staffordshire have signed up to the scheme.
The dogs, who are more used to working in pubs and clubs, are experts at sniffing out drugs.
Anyone carrying any drugs on them is sure to get caught.
The parents of pupils will be told about the sniffer dogs' first visits to the schools - but after that, the animals will be brought into schools without warning.
The leader of one local council said: "We believe these visits will help to deter young people from becoming involved with drugs.
"I am confident this excellent initiative will improve the safety and well-being of young people in our district."