Three people were arrested after the 44-year-old man suffered a serious stab wound at the flat in Chadwick Close on Saturday afternoon.
The three, who are understood to be known to the victim, were later released without charge.
The victim remained in hospital on Wednesday morning, police said.
A spokesman for West Midlands Police said: "A man suffered a serious stab wound to his chest following a disorder at a flat in Chadwick Close, Wolverhampton on Saturday.
"Paramedics were called to the address at around 4.30pm and transferred a 44-year-old man to hospital; his condition is not life threatening.
"We arrested three people from the address – a 30-year-old woman plus men aged 39 and 36 – in connection with the stabbing.
"The people arrested – who are all understood to be known to the victim – were later released without charge."
Jordan Eggington, spokeswoman for West Midlands Ambulance Service, said: "We were called at 4.18pm on Saturday to reports of a patient with stab injuries at Kingsclere Walk, Merry Hill.
"We sent one ambulance, a paramedic officer, the Midlands Air Ambulances from Strensham and the critical care car with a critical care paramedic on board.
"Crews treated one patient, a man, for injuries not believed to be life threatening and he was conveyed to hospital for further treatment.”