A 30-year-old man has been arrested after an assault outside a bar in Harrow.
Officers were called by the London Ambulance Service to Station Road at around 3.30am on Saturday.
Trinity Bar is currently cordoned off with a forensics team seen working in the area on Saturday.
A 31-year-old man was taken to hospital. Metropolitan Police are awaiting an update on his condition.
A 30-year-old man has been arrested on suspicion of grievous bodily harm. He remains in police custody.
A spokesperson for the Metropolitan Police said: "At around 03.29hrs on Saturday, 8 August, police were called by London Ambulance Service to reports of an assault on Station Road, Harrow.
"A 31-year-old man was taken to hospital, and we are awaiting an update on his condition.
“A 30-year-old man has been arrested on suspicion of grievous bodily harm.
"He was taken into custody where he remains. Enquiries remain ongoing."
Anyone with information that may assist police is asked to call 101, quoting CAD1145/08AUG.
