TripleManía XII was the eighteenth overall TripleManía wrestling show promoted by Asistencia Asesoría y Administración (AAA). The show took place on June 20, 2004 in Naucalpan, Mexico like the previous year's event. The Main event featured a Luchas de Apuestas "Mask vs. mask" match between La Parka and Cibernético.
The event featured six professional wrestling matches with different wrestlers involved in pre-existing scripted feuds, plots and storylines. Wrestlers were portrayed as either villains (referred to as rudos in Mexico) or fan favorites (técnicos in Mexico) as they followed a series of tension-building events, which culminated in a wrestling match or series of matches.
- (c) refers to the champion(s) heading into the match.
- Oscar Sevilla, Pimpinela Escarlata, Cinthia Moreno and Mascarita Sagrada defeated Gran Apache, Polvo de Estrellas, Faby Apache and Mini Abismo Negro in a Eight-man "Atómicos" tag team match
- Octagón, Heavy Metal and El Intocable defeated Pirata Morgan, MS-1 and Espectro, Jr. via DQ in a Six-man "Lucha Libre rules" tag team match
- Latin Lover, Héctor Garza and Gronda defeated Abyss, Chessman and Abismo Negro in a Six-man "Lucha Libre rules" tag team match
- Charly Manson defeated Electroshock in a Singles "Retirement" match. After Electroshock lost the match his wife, Lady Apache, convinced Charly Manson not to make Electroshock retire in return she would shave off her hair. After wards Electroshock also shaved his own hair in sympathy with his wife's sacrifice.
- As a result Cibernético was unmasked.