Police were called to Wandsworth Bridge Road, SW18 at 10pm on Thursday, 23 March to reports of a stabbing.
Officers attended. A man was found with a slash wound to his face. Another man was found with a hand injury.
They were treated at the scene by paramedics from London Ambulance before being taken to the hospital.
A man was arrested at the scene on suspicion of causing GBH.
A crime scene has been put in place.