The 18-year-old man was taken to hospital after he was injured by at least two attackers near Dovecote Primary School in Pendeford on Monday afternoon. His injuries were described as 'superficial' by police.
The attack is believed to have happened on Ryefield, which links The Droveway with Barnhurst Lane, as children were travelling home from school at around 4pm.
A section of the road next to the primary school and Pendeford Seventh-day Adventist Church was blocked off by police as a result.
Photos taken at the scene showed a National Express bus left stranded behind the police cordon.
Nobody has been arrested and officers are appealing for anybody who witnessed the incident to get in touch.
A West Midlands Police spokesman said: "A man was taken to hospital with superficial slash wounds just after 4pm yesterday.
"The 18-year-old is thought to have been injured on Ryefield, Wolverhampton a short time earlier by at least two offenders.
"An area has been cordoned off and investigations are on-going and anyone who saw what happened is asked to call police on 101."