The aim of this study is to identify factors associated with Vietnamese-Australian parents' language use and attitudes towards home language maintenance. Vietnamese-Australian parents (n = 151) with children aged under 18 completed a survey regarding demographic factors and factors conceptualised by Spolsky's language policy theory: language practices, language ideologies, and language management. Bivariate analyses and multiple regression models were conducted to explore associations between parents' language use and their attitudes towards home language maintenance and associated factors. "Parents' language use with their child" was significantly associated with their language practices (parents' language use in social situations). "Parents' language use in social situations" was significantly associated with language practices (parents' Vietnamese and English proficiency, parents' language use with their child), language management (frequency of attendance at community events), and one demographic factor (age). "Parents' attitudes towards home language maintenance" was significantly associated with language ideology factors (perceptions of cultural identity, belief in the importance of English language maintenance, belief that home language strengthens relative bonds and widens career options), and one demographic factor (income). The results can be used to assist families with Vietnamese heritage to maintain their home language by informing targeted approaches to supporting language maintenance at the community and family level.