|Founded by||Alfredo Beltran Leyva|
|Founding location||Mazatlán, Sinaloa, Mexico|
|Territory||Sinaloa, Sonora, Durango, Nayarit|
|Leader(s)||Fausto Isidro Meza Flores,|
|Criminal activities||Murder, kidnapping, extortion.|
|Allies||Beltrán Leyva Cartel, Los Zetas|
|Rivals||Sinaloa Cartel, Los Ántrax|
Los Mazatlecos gang were formed in the coastal city of Mazatlán, Sinaloa, from where they take their name. Initially, the gang was at the service of the drug lord Alfredo Beltrán Leyva ("El Mochomo") until he was arrested by the Mexican authorities in 2008. After his arrest, Los Mazatlecos shifted their alliance to Alfredo's brother Héctor Beltrán Leyva, the current leader of the Beltrán Leyva Cartel. The group is one of the largest gangs working for the cartel's criminal umbrella.
- "The Gang That Took on Chapo: Los Mazatlecos". Borderland Beat. 28 July 2012. Retrieved 20 December 2012.
- Vega Gutiérrez, Aurora (7 April 2012). "El narco provoca éxodo en Sinaloa; 665 familias abandonan la entidad". Excélsior (in Spanish). Retrieved 20 December 2012.