This study explores language shift and maintenance of Indigenous languages in bilingual contact situations. It specifically examines how factors such as language attitudes favour and deter the use, maintenance and transmission of Nahuatl. Data on language attitudes were collected by means of interviews which covered the linguistic background, language use, language significance, language shift, language maintenance, and evaluations of Nahuatl varieties. Fifty-two adults, comprising bilinguals and Nahuatl monolinguals, were interviewed in either Nahuatl or Spanish. The general themes identified in the interviews were pro-Indigenous attitudes, referring to the importance of Nahuatl to individuals and the community, purist attitudes, concerning Nahuatl use, and anti-Indigenous attitudes, questioning the relevance of Nahuatl for socioeconomic advancement. The findings provide insight into the intergenerational transmission, language use in the home and community, language education, speakers' beliefs, and internal and external influences about Nahuatl in Mexico. They provide new insights into the perspectives of adults who represent the parent and grandparent generations, important groups responsible for the transmission of Nahuatl to the younger generations.