Despite a general expectation for immigrants to Australia to shift quickly to the use of English, many new-Australian families maintain strong attachments to their heritage languages. Little research has explored how recently arrived families of Arabic-speaking background in Australia preserve their heritage language while acquiring proficiency in English. In this paper, we report on part of a study that explored the family language policies of four Arab-Australian mothers as they negotiated their new language reality. Focus groups and semi-structured interviews revealed that the participating mothers considered it vitally important for their children to be proficient in both English and Arabic and they employed a range of strategies for developing their children’s bilingualism. However, they also acknowledged that maintaining their children’s heritage language could be difficult and stressful. Our paper offers insights into family language policy and the challenges of heritage language maintenance for bilingual immigrant mothers in assimilationist contexts.