The cacique also mediates differences between local groups. Village exogamy is practiced. The mataco also have the custom of bride service. After this service has been completed and until their first child is born, the married couple live in the husband's village. Thereafter, residence is matrolocal.
Descent is matrilineal, and kinship terminology is of the Hawaiian type.
Ceremonies are important to the Mataco. During ceremonies, dancing, drum playing, drinking, and chanting are all thought to ward off evil spirits. The Mataco pray to guardian spirits for supernatural aid. In ceremonies performed to prevent disease, the Mataco tattoo their bodies using soot or ashes as pigment. Bleeding and scarification, as well as the ownership of sacred objects, are also believed to be effective in preventing disease.