The 62-year-old man's body was found at the flat in Tettenhall Road on Tuesday afternoon.
Officers from West Midlands Police visited the flat on Tuesday to check on the welfare of the man, after they received a 999 call just before 2.20pm to say there were concerns for him. Once inside the flat, near to the junction of New Hampton Road West, officers found the man's body.
His death is currently being treated as suspicious, with detectives and forensic investigators gathering information from the scene.
The large team, supported by local officers, have spoken to people in the area – and are examining CCTV footage and other evidence.
Detective Inspector Laura Harrison, from Force CID, said: "We have not yet formally identified the 62-year-old but we have told his family the sad news and that we believe the man to be their loved one.
"We are working hard to get answers for them and we will be keeping them updated about our investigation.
"We extend our condolences to the man's family and friends."
Anyone who lives in the area is being urged to check their CCTV or video doorbell footage – and inform police if they see anything suspicious.
People who live in the area are also urged to report any suspicious behaviour leading in the days leading up to Tuesday.
Anyone with information can call West Midlands Police on 101, quoting reference number 488-20072021.
Alternatively, call Crimestoppers anonymously on 0800 555111.