This paper examines the status and use of language in the Nuba Mountains, Sudan. It is based on responses to 1496 questionnaires administered to people belonging to 37 different ethnic groups. Subjects were asked about language proficiency, language use in different domains and language attitudes. Factors such as sex, generation, intermarriage, education and urbanisation were correlated to the process of language shift among the groups under investigation. The results suggest a clear language shift towards Arabic across many different groups, especially the Dilling, Ama and Gulfan. Education and urbanisation were found to have strong effects on the shift away from ethnic languages. Women appear to have taken the lead in the process. Their growing role in socioeconomic life and the increasing opportunities for women to get an education have been among the main impetuses for women to abandon their own ethnic languages. (Contains 8 tables.)