As of March 20, 1998, Mexican law recognizes dual nationality for Mexicans by birth, meaning those born in Mexico or born abroad to Mexican parents. U.S. citizens who are also Mexican nationals are considered Mexican by local authorities. Therefore, their dual nationality status could hamper U.S. Government efforts to provide consular protection. But dual nationals are not subject to compulsory military service in Mexico.

Travelers possessing both U.S. and Mexican nationalities must carry with them proof of their citizenship of both countries.

Under Mexican law, dual nationals entering or departing Mexico must identify themselves as Mexican.