Medics were called to Bishopsford Road on Saturday (April 26) at 8.15pm after reports of a knife attack.
Ambulances first arrived on scene in five minutes and a teenager was found with stab injuries.
The teen, whose age and gender has not been shared at this time, was taken to hospital as a priority.
Their condition is not known at this time.
A London Ambulance Service spokesperson said:“We were called at 8.15pm on Saturday 26 April to reports of a stabbing on Bishopsford Road, Morden.
“We sent an ambulance crew an incident response officer and a clinical team manager to the scene.
“Our first paramedics arrived on scene in five minutes.
“We treated a teenager and took them to a major trauma centre as a priority.”
The Metropolitan Police has been approached for comment.
