The Metropolitan Police was called to Mitcham Road just before 11pm on Friday (November 28) regarding a collision between two cars.
A 59-year-old man was arrested on suspicion of drink driving but has been released under investigation.
The London Ambulance Service took a man to hospital, where his condition is currently unknown.
The Met will carry out enquiries, and anyone with any information is asked to call 101 quoting 8500/28Nov.
A spokesperson for the Metropolitan Police said: “On Friday, 28 November at 22:59hrs police were called to reports of a road traffic collision between two cars in Croydon.
“Officers joined the London Ambulance Service at the scene on Mitcham Road.
“A 59-year-old man was arrested on suspicion of drink driving. He remains in custody.
“Enquiries are ongoing.
“Anyone with information that may assist police is asked to call 101 quoting 8500/28Nov.”
