All gasoline-powered passenger cars and light trucks between three and 25 years old in the following Georgia counties must pass an emission inspection before being issued license plates:

Cherokee

Clayton

Cobb

Coweta

DeKalb

Douglas

Fayette

Forsyth

Fulton

Gwinnett

Henry

Paulding

Rockdale
http://www.dmv.org/ga-georgia/smog-check.php