A Pinner man has been charged on suspicion of stabbing his brother in the chest with a kitchen knife.
The 24-year-old victim was taken to St Mary's Hospital in central London after the attack in Pinner Hill Road, between 2-2.30am on Sunday.
He is believed to be in a serious but stable condition.
Forensic officers taped off the crime scene while they collected evidence, however police confirmed the knife used in the attack has not been recovered.
Luke Stuart, 24, of Mercer Place, Pinner, appeared at Harrow Magistrates' Court on Monday morning charged with possessing an offensive weapon and wounding with intent. He is due to appear at Harrow Crown Court in January next year.
Mohamed Naseer, 34, of Pinner Hill Road, said: "I looked out my window and saw an ambulance.
"I could see a man lying there and he was screaming.
"It is really frightening to think something like this happened so close to where I live, especially as I have two children."
Debbie Steers, chairwoman of Pinner Hill Residents and Tenants' Association, was shocked by the attack.
She said: "This is just too close to home. Everyone in the area is talking about it. I woke up on Sunday and saw forensic officers and a tent at the crime scene. It sends shivers down your spine.
"I have younger members of my family who live in the area and I just constantly worry about them.
"This area is getting worse for crime. To hear that someone has been stabbed is really scary."
Detective Inspector Richard Metcalfe, of Harrow CID, is appealing for witnesses to come forward with information.
He said: "The investigation quickly identified the suspect who was almost immediately arrested, and police are looking for no suspects in this incident.
"It is a knife-related incident and the community can be reassured that the police take knife crime seriously.
"Police are appealing for witnesses who may have seen any part of this incident between 1am and 3am on November 2."
Yesterday morning (Wednesday) the stabbed man was said to be in a stable condition. * Anyone with information should call 020 8733 3462.