Cobb County police say the shooting happened 2:30 a.m. Tuesday near Interstate 285 and Powers Ferry Road.
Cobb police spokesman Mike Bowman tells The Atlanta Journal-Constitution that the officer was taken to a hospital in stable condition.
WSB-TV reports that several police agencies were searching for two men and a woman and a helicopter was being used in the hunt for the suspects.
Authorities say the shooting appears to have taken place during a traffic stop. Police said the officer pulled over a blue Volvo. Police said the car was being following by a red Dodge Stratus with Georgia tag PJG 7617, which officers are now searching for.