Residents have spoken of their shock after a woman was found with a serious head injury in a quiet neighbourhood.
Emergency services descended on Harcourt Road in Bitterne on Monday evening where a 34-year-old woman was treated by paramedics for serious head injuries.
It took place just after 7.30pm.
Hampshire police have arrested a 45-year-old man from Southampton on suspicion of attempted murder. He remains in custody as enquiries continue.
A resident who lives nearby said: "I was out until about 11 or 12, I didn't notice anything.
"It is not something you want to hear when you get home around here. It is concerning."
Another neighbour described seeing emergency services arrive and recalled the distressing scene.
He said: "I just saw ambulances arrive then five or six police cars that arrived. They were here from about 7.30pm to about 9.30pm.
"I had seen them wheel the lady on a stretcher. This is crazy, it is not normal for this area at least. A good police presence at least, and then the air ambulance as well."