People close to the man became concerned about his whereabouts on Saturday after he left his apartment around 10.30pm on Friday to go either to his basement storage room or garage, cantonal police said.
The 37-year-old victim, a Swiss citizen, never returned.
Police officers arrived at the apartment building at 29 Chemin de la Traille, where they discovered the man’s lifeless body in his garage.
A prosecutor, inspectors from the criminal brigade, a forensic doctor and other specialists were called to the scene to investigate.
The officers rapidly concluded that the cause of the death was a criminal act, police said.
Citing a source close to the investigation, the Tribune de Genève reported online that the man was savagely beaten.
The area around the building was cordoned off and investigators questioned people who knew the victim, police said.
The Tribune de Genève reported that neighbours were apprehensive about the murder of someone who had lived in the neighbourhood for a long time and had a reputation for being polite.
But the newspaper quoted police spokesman Eric Grandjean saying that there was no cause for the population at large to be concerned for their safety.
"There is no danger," he said.
"This is not about a break-in that turned bad nor a gratuitous attack that happened by accident."
The Tribune said police suspect the case was a settling of accounts.
"The victim probably had a meeting with his attacker or attackers," a source close to the investigation told the newspaper.
Police said the investigation was still under way and no arrest had been made.
The death marked the second murder in the canton of Geneva so far this year.