Prosecutors in the state of Guanajuato said two other men were wounded in the shooting. The attack occurred before dawn Saturday in the town of Cueramaro, near the border with Jalisco state.
There was no immediate information on a possible motive in the attack.
However, the Jalisco drug cartel has been fighting to take over territory in Guanajuato from local gangs. Guanajuato is a farming and industrial state with the highest number of homicides in Mexico.