Text-to-speech technology can act as an important support tool in computer-based learning environments (CBLEs) as it provides auditory input, next to on-screen text. Particularly for students who use a language at home other than the language of instruction (LOI) applied at school, text-to-speech can be useful. The CBLE E-Validiv offers content in the LOI and one of six other languages. All content can be read aloud via text-to-speech. For students having a home language other than the LOI, the other language is set to their home language; students who use the LOI at home mostly have English or French available. This study aimed to determine fifth-grade students' use of bilingual text-to-speech and examine student characteristics related to this use (n = 360). Multilevel hierarchical regression analyses show that particularly students having their home language available apply text-to-speech in their home language. However, their main focus remains on text-to-speech in the LOI. Students with a low self-assessed proficiency in their home language and those who often watch television and read books in the LOI use text-to-speech more in the LOI. Considerations for practice, the design of CBLEs with text-to-speech and future directions for research are discussed.