Primera División A (Méxican First A Division) is a Mexican football tournament.
This season was composed of Apertura 2004 and Clausura 2005.
The Promotion Final faced San Luis against Querétaro to determine the winner of the First Division Promotion.
The Football Association determined the celebration of a promotion series between the penultimate team of the Primera 'A' Relegation Table against the runner-up of the Second Division, this series faced Chivas La Piedad against the Cachorros UdeG.
Chivas La Piedad won the series and remained in the category.