General elections were held in Mexico on July 6, 1988.
Carlos Salinas de Gortari was declared the winner, with the Ministry of Interior saying he had received 50.7% of the vote. It was the lowest for a winning candidate since direct elections were introduced for the presidency in 1917. In the Chamber of Deputies election, the Institutional Revolutionary Party won 260 of the 500 seats, as well as winning 60 of the 64 seats in the Senate election. Voter turnout was said to be 51.6% in the presidential election, 49.7% for the Senate elections and 49.4% for the Chamber election. This was the first time that a parallel vote tabulation was implemented in Mexico, the results were informed by telephone from the electoral districts to the secretariat of the Interior. During the parallel vote tabulation, the secretary of the interior said that the telephone network was saturated, characterizing it as "a breakdown of the system." Former president Miguel de la Madrid later admitted that this "breakdown" was a fabrication. One observer said, "For the ordinary citizen, it was not the network but the Mexican political system that had crashed." Although early results of the parallel vote tabulation had indicated Cuauhtemoc Cárdenas was winning, when the official results were announced, Salinas was said to have eked out a narrow victory.
Years later, former president Miguel de la Madrid admitted in an autobiography that there was not yet any official vote count when the PRI declared Salinas as the winner. In 1991, the ruling PRI and the opposition PAN approved a motion to burn all the ballots, therefore removing all evidence of the fraud. A 2019 study in the American Political Science Review found "evidence of blatant alterations" in approximately one third of the tallies in the election.