The lawsuit claims that the activities of gun companies have led to an increase in violence in Mexico.
The Mexican government has sued American manufacturers and distributors of weapons, claiming that their commercial practices have led to increased violence in the country.
An unusual lawsuit was filed in the US federal court in Boston.
Among the defendants are the largest US arms companies.
According to the lawsuit, the companies know that their activities contribute to the illegal import of weapons into Mexico.
Mexico is demanding compensation for the damage caused to its country by weapons.
The sale of firearms in Mexico is strictly limited, but powerful drug cartels smuggle thousands of weapons into the country.