Primera División de México Apertura 2004
Primera División de México ' Apertura 2004''' is a Mexican football tournament - one of two short tournaments that take up the entire year to determine the champion of Mexican football. It began on Saturday, August 14, 2004, and ran until November 20, when the regular season ended. Dorados de Sinaloa was promoted to the México Primera División thus, San Luis, Irapuato and Querétaro were all relegated to the Primera División A, making it 18 teams in the Primera División as opposed to 20. On December 11, UNAM defeated Monterrey and became champions for the fifth time.
Overview
| Team | City | Stadium | - |
| América | Mexico City | Azteca | - |
| Atlante | Mexico City | Azteca | - |
| Atlas | Guadalajara, Jalisco | Jalisco | - |
| Chiapas | Tuxtla Gutiérrez, Chiapas | Víctor Manuel Reyna | - |
| Cruz Azul | Mexico City | Azul | - |
| Guadalajara | Guadalajara, Jalisco | Jalisco | - |
| Morelia | Morelia, Michoacán | Morelos | - |
| Monterrey | Monterrey, Nuevo León | Tecnológico | - |
| Necaxa | Aguascalientes, Aguascalientes | Victoria | - |
| Pachuca | Pachuca, Hidalgo | Hidalgo | - |
| Puebla | Puebla, Puebla | Cuauhtémoc | - |
| Santos Laguna | Torreón, Coahuila | Corona | - |
| Sinaloa | Culiacán, Sinaloa | Carlos González y González | - |
| Toluca | Toluca, State of Mexico | Nemesio Díez | - |
| UAG | Zapopan, Jalisco | Tres de Marzo | - |
| UANL | San Nicolás de los Garza, Nuevo León | Universitario | - |
| UNAM | Mexico City | Olímpico Universitario | - |
| Veracruz | Veracruz, Veracruz | Luis "Pirata" Fuente |
Final standings (groups)
League table
Results
Top goalscorers
Players sorted first by goals scored, then by last name. Only regular season goals listed.| Rank | Player | Club | Goals |
| 1 |  Guillermo Franco | Monterrey | 15 |
| 2 |  José Cardozo | Toluca | 12 |
| 2 |  Robert de Pinho | Atlas | 12 |
| 4 |  Rafael Márquez Lugo | Morelia | 11 |
| 4 | Vicente Matías Vuoso | Santos Laguna | 11 |
| 6 | Luciano Figueroa | Cruz Azul | 10 |
| 6 |  Sebastián González | Atlante | 10 |
| 8 | Walter Gaitán | UANL | 9 |
| 9 | Jared Borgetti | Sinaloa | 8 |
| 9 | Salvador Cabañas | Chiapas | 8 |
Source:
Playoffs
Bracket
Quarterfinals
Monterrey won 3–2 on aggregate.----
Atlante won 8–5 on aggregate.
----
Atlas won 4–3 on aggregate.
----
UNAM won 4–1 on aggregate.
Semifinals
Monterrey won 7–3 on aggregate.----
UNAM won 6–4 on aggregate.