Zimmerman and the man who shot at him had been in an ongoing dispute, police in Lake Mary, Florida, said, though both men involved in the incident were yet to be interviewed by police, pending the presence of their attorneys.
No arrests have been made or charges filed in relation to the shooting, which is in the early stages of the investigation.
Lake Mary police spokeswoman Bianca Gillett confirmed that the man who shot at Zimmerman, Matthew Apperson, is the same person who called police last year because he felt threatened by Zimmerman.
According to police, Zimmerman flagged down a Lake Mary police officer shortly after 1 p.m. Monday, saying he was involved in a shooting.
At about the same time, someone called 911 for Apperson to say he was the other person involved in the shooting.
Zimmerman was not the shooter in the incident, Gillett said. He was transported to the hospital for minor injuries and then released, she said.
The details of what led to the shooting will be determined by the ongoing investigation, Gillett said.
Meanwhile, conflicting versions of the incident have emerged from the two men involved.
Attorney: Zimmerman recognized Apperson
Zimmerman attorney Don West told CNN that a driver behind Zimmerman began flashing his lights and honking his horn at him.
"The man pulled up next to George yelling obscenities at him," West said.
Zimmerman recognized Apperson as someone he had a problem with several months ago.
According to West, Zimmerman raised his window and then the man shot at him.
The bullet went through Zimmerman's side window and almost hit him in the head, West said. Zimmerman was hit by glass from the window, he said.
'I shot George Zimmerman, call 911'
An employee at a nearby business, Kenneth Cornell, said he was exiting his car after lunch when a man drove up and started yelling about the shooting.
The man, who identified himself as Apperson, shouted to Cornell: "I shot George Zimmerman, call 911. I don't have a phone."
So Cornell called 911. He said Apperson shot Zimmerman after Zimmerman waved a gun.
Apperson's attorney, Mark NeJame, said his client acted in self defense.
"What happened today, he was legally justified to do," NeJame said Monday.
But West, Zimmerman's lawyer, denied that his client waved a gun. "George absolutely denies pointing a gun, displaying a gun -- no aggressive movement toward him at all," West said.
Police arrived minutes after he called 911, Cornell said. Police have not verified Cornell's account to CNN.
According to Cornell, Apperson told him that he and Zimmerman have had three disputes.
At least one previous dispute between Zimmerman and Apperson had been reported to police. In September 2014, Apperson called 911 after allegedly being threatened by Zimmerman.
Apperson told police that Zimmerman threatened to shoot him dead, and even though the man says he did not see Zimmerman flash a gun, he was still threatened enough and worried enough to call police.
Two days later, police stopped Zimmerman after Apperson called 911 to say he thought he saw Zimmerman near his office.
The police report says Zimmerman told him he was in the area for an appointment. He also admitted to being involved in a verbal incident earlier in the week but denied threatening anyone.
Apperson did not pursue charges against Zimmerman.
History of run-ins with the law
Monday's shooting is the latest headline-grabbing incident for Zimmerman since his acquittal in July 2013 on a murder charge in the death of Martin, a 17-year-old African-American.
Zimmerman fatally shot Martin on February 26, 2012.
On that day, Zimmerman, a neighborhood watch captain in Sanford, Florida, called 911 to report "a suspicious person" in the neighborhood.
The dispatcher asked him whether he was following the person, and Zimmerman replied that he was "trying to find out where he went."
He ignored the dispatcher's advice not to follow the person, and according to later accounts by Zimmerman, Martin jumped toward him and a fight ensued.
Moments later, neighbors report hearing gunfire.
Zimmerman was pulled over for speeding in northern Texas in July 2013, a few weeks after he was acquitted of Martin's death.
He apparently had a firearm in the glove compartment of a vehicle, prompting an officer to tell him, "Don't play with your firearm, OK?"
He was sent on his way with a warning.
In November of that year, police took him into custody at his then-girlfriend's home in Apopka, Florida, after an apparent fight.
He was arrested on aggravated assault and misdemeanor counts of domestic violence battery and criminal mischief, but the woman later asked that the charges be dropped and Zimmerman was not prosecuted.
Then, in January, he was arrested on another domestic violence complaint after he allegedly threw a wine bottle at a girlfriend, his lawyer Don West told reporters at the time. She later recanted and charges were never filed, CNN affiliate WESH reported