|Region||State of Mexico|
|Native speakers||<1,500 (date missing)|
ocu – Ocuiltec/Tlahuica
mat – Matlatzinca
The Matlatzinca language, also called Tlahuica or Ocuiltec, is an indigenous language of Mexico spoken by the Matlatzinca people in the southern part of the State of Mexico. It is an Oto-Manguean language of the Oto-Pamean subgroup. The name of the language in the language itself is pjiekak'joo, "The language that I speak".
The Matlatzinca language has two subgroups or dialects that are mutually unintelligible: one called Ocuiltec or Tlahuica and Matlatzinca proper. While originally one language they are now so removed that they are often considered separate languages. Matlatzinca is spoken by around 1000, mostly elderly people in San Francisco Oxtotilpa, and Ocuiltec/Tlahuica spoken by around 400 in Ocuilan municipio in the villages San Juan Atzingo and Santa Lucía del Progreso.
Because of the extremely small population and the unfavourable age structure, the Matlatzincan languages are considered to be highly endangered. In the 2000 census, only 26 persons under the age of 20 were registered as speakers of Ocuiltec.
In 2001, together with 62 other languages, it was recognised by a statutory law of Mexico as an official language in the Mexican Federal District and the other administrative divisions in which it is spoken, and on an equal footing with Spanish.
See also 
- The Ley General de Derechos Lingüísticos de los Pueblos Indígenas ("General Law of the Linguistic Rights of Indigenous peoples"), decree published 13 March 2003