This study was conducted to determine the level and degree of stability of bilingualism (German-Spanish) in two German communities in Chihuahua, México. The cornmunity of Colonia Capulín was selected because it was representative of the most fundamental and conservative Mennonite groups. A former Mennonite group in Colonia Swift Current was selected to provide a contrast because it was undergoing a significant degree of a cculturation and modernization.A household survey, interviews, and sustained observation yielded the salient sociolinguistic characteristics of selected societal domains in both communities. Only the obvious language use and preference pattems that emerged from the survey were included as preliminary findings. It was concluded that the fundamental community in Colonia Capulín had stable bilingualism, while the group in Colonia Swift Current was best characterized by transitional bilingualism.