It is understood the incident on Lidgett Lane in Roundhay involved a large group of teenagers.
A 16-year-old boy suffered a head injury and was taken to hospital.
Police have arrested four people in connection with the incident.
Detective sergeant Marcus Dawson, of Leeds District CID, said: “Police were called at 3.37pm today [June 2] to a report of a fight involving a number of people in Lidgett Lane, Leeds.
“A 16-year-old boy was found at the location with a head injury and has been taken to hospital for treatment.
“Four people have been arrested and are currently in custody.
“Officers are still establishing the exact nature of what has occurred and are making a number of enquiries at the scene.
“Anyone who witnessed this incident or who has any information which could help the investigation is asked to call Leeds District CID on 101 or pass information anonymously to Crimestoppers on 0800 555 111.”