- The Gambetti Family.
- The Pavano Family.
- The Messina Family.
- The Lupisella Family.
- The Ancelotti Family.
- Don (Boss)
- Consigliere (Advisor)
- Capo (Captain)
The gang carries pistols, shotguns, submachine guns, knives and otherwise fight with their fists. The mobsters usually carry one or two weapons during gameplay as noted from Grand Theft Auto: San Andreas and Grand Theft Auto IV.
New York City Commission
The Commission in GTA IV is based on New York City's real Mafia Commission: The five families in New York City's Commission are:
- The Gambetti-Ancelotti rivalry is possibly based on the Gambino-Colombo war, as they are the only two families in the New York City Commission that are not allied with each other.
- In the The Lost and Damned, before you fight them in Gang Wars, Clay will sometimes say "Lets teach those Mobsters it ain't the 70's anymore".
- There is an easy way to tell if a pedestrian in Little Italy is in the Mafia by pushing them (this will result in them fighting back), then pull out a gun, they will take out either an SMG, Combat Shotgun, or Pistol.