A man in his 50s has been arrested on suspicion of murder following a stabbing at a house, police have said.
Avon and Somerset Police said it was called to Honeysuckle Close in Bradley Stoke, Bristol, at about 03:20 GMT on Saturday after reports a man had been stabbed and was critically wounded.
Emergency services attended but the man was pronounced dead at the scene.
The suspect received hospital treatment but was then discharged and is now in custody.
A police cordon remains in the area, but it is believed to have been an isolated incident.
Formal identification has yet to be completed but police believe the victim to be a man in his 30s. His next of kin has been informed.
Det Insp Mark Newbury, of the Major Crime Investigation Team, said: "Our thoughts go out to the man's family following yesterday's tragic events.
"Our investigation is at an early stage, but at this moment in time we'd like to reassure the people of Bradley Stoke this is believed to have been an isolated incident."
There will be an increased police presence in the area, Avon and Somerset Police added.