The 1977/78 season was the 35th regular championship round in Mexico since the introduction of the Primera División in the 1943/44 season.
The relegated from the previous season , CD Zacatepec , was replaced by the promoted CF Atlante. Last year's promoted San Luis FC , who had played an excellent round last season and reached the finals of the top 8 teams, also had to say goodbye after selling their license to the newly added team from CD Tampico.
As already practiced in the previous season, the competition was divided into 4 groups of 5 teams each. Regardless of this, each team in the league continued to play against each other twice (in one home and one away game). At the end of the league round, the two best-placed teams in each group qualified for the final round, which was played in the knockout system from the quarterfinals .
In the battle for relegation, the two lowest point groups in the relegation round faced each other. The team from Unión de Curtidores prevailed against Club Atlas, which had to accept its third overall descent into the second division .
