Mr Combs "fired a shot" into the ceiling of Manhattan's Club New York, assistant district attorney Matthew Bogdanos said in opening statements.
"Witnesses will say they saw the muzzle flash."
Three people were injured in the shooting incident at the club in December 1999.
Mr Combs is not accused of shooting anyone, but he could face up to 15 years in jail if found guilty of charges for possession of a weapon, and trying to bribe his driver to take the blame.
His girlfriend, actress and singer Jennifer Lopez, did not attend the opening day of the trial in the Manhattan courtroom. "If they need me, I'll be there," she said.
Charges
Mr Combs was arrested after he fled the club with Ms Lopez, who has not been charged.
Co-defendant Jamal Barrow faces charges of attempted murder and gun possession, while bodyguard Anthony Jones is accused of having the loaded gun by his feet.
Mr Combs' defence team said the prosecution was picking on their client because of his fame.
"This was a star-struck selective prosecution of a superstar," said defence lawyer Benjamin Brafman.
"This prosecution is about fame and celebrity, not about a search for truth and justice."
Mr Brafman is best known for defending leading mafia figures. The defence team also includes Johnnie Cochran, who represented OJ Simpson.
Car chase
Mr Bogdanos told the court that as Mr Combs, Ms Lopez and Mr Jones drove away from the club with driver Wardell Fenderson, someone threw a handgun out of the vehicle's window.
When police stopped them after they had run through several red lights another pistol was found on the floor in front, he said.
Prosecutors say Mr Combs and Mr Jones tried to bribe Mr Fenderson into claiming that the gun was his. Mr Combs allegedly offered Mr Fenderson $50,000 and a diamond ring given to him by Ms Lopez.
The shooting in the club allegedly happened after a man insulted Mr Combs and threw money in his face.
Metal detector
Mr Bogdanos said that patrons entering the club are required to walk through a metal detector, but Mr Combs and his group were not searched.
"You don't search Puff Daddy and his entourage," he said. "No one lays a glove on them."
The mixed-race jury took six days to select, with six alternative jurors chosen to be on standby.
Court officials say they expect the trial to run for between five and six weeks.
The three people injured in the shooting are each seeking a $100m settlement.