The Brady Center to Prevent Gun Violence charges the Second Amendment doesn't give government the right to require individuals to possess firearms, the group said on its website.
The Brady Center said the law enacted by Nelson, Ga., population 1,314, forces citizens to buy guns against their will, regardless of whether they need them or know how to use them.
It also charges the law violates residents' right to privacy and freedom of speech and discriminates against non-heads of households.
"Most Americans reject the gun lobby's vision of an America in which the government can force guns into every sector of society," Brady Center Legal Action Project Director Jonathan Lowy said in the release. "In this lawsuit we seek to establish that the government does not have the authority to compel Americans to buy guns or bring them into their homes."
The lawsuit cites the case of Nelson resident Harold Kellett, 75, who spent almost $700 on a Remington handgun and ammunition.
"The firearm ordinance inflicted a concrete economic harm on Mr. Kellett by forcing him to purchase a firearm and ammunition," the complaint states.
Kellett isn't named as a party to the suit.
The suit, filed in the U.S. District Court for the Northern District of Georgia, asks the court to annul the law.