This paper examines the link between strength of ethnic identity and extent of ethnic language use for some indigenous speech communities in Sarawak, Malaysia. The domains of language use examined are mass media, education, transactions, friendship, religion, and family. A total of 568 indigenous adolescents in six secondary schools in Sarawak from both urban and rural localities participated in a survey. The results show that ethnic language use is the most extensive among the Penan, followed by the Iban, Saban, and Kelabit. Ethnic language use is relatively low for the Kenyah, Melanau, Murut, and Bidayuh. The findings suggest that ethnic language use is more extensive in groups that are numerically dominant, who live in their ancestral home area, and whose language has less regional variation. However, participants from various Sarawak indigenous groups were similar in their positive attitudes toward their ethnic identity, and the range of variation is narrow. The results indicate that strength of ethnic identity and extent of ethnic language use are not directly linked for the Sarawak indigenous speech communities examined. In such contexts, language maintenance may not be the main reason for cultural maintenance, even though it is still relevant for the preservation of cultural knowledge.