Police were called to The Preston pub, in Preston Road, Wembley, at 11.40pm on Saturday (November 30) following reports of a “disturbance” involving a group of men.
Three men were assaulted, and one man had to be taken to hospital after sustaining “serious injuries”.
Officers arrested a 36-year-old man on suspicion of wounding with intent to cause grievous bodily harm.
A spokesperson for the Metropolitan Police has confirmed that the 36-year-old remains in custody, and enquiries into the incident are ongoing.
Anyone with information is urged to call the police on 101 or post @MetCC, referencing CAD 8068 of 30 November.
To remain 100% anonymous contact the independent charity Crimestoppers on 0800 555 111.