Clients pay up to £1,000 a year to have access to guards who, in addition to street patrols, will meet their children off the school bus and walk them home.
Security firms say demand is particularly high for the tough former Nepalese soldiers.
Hocroft Trading and Security in Hampstead, north-west London, receives up to 30 calls a day from parents who are interested in its meet-and-greet service.
Director Abi Mohamed said: “They are scared. It just makes them feel better to know someone is there until their child is inside the house.”
Bishnu Tamang, manager of Gurkha Security Services, has clients in west London and the Midlands.
He said: “We run a service where we accompany children to school and the same on their journey home.”