This study examines how immigrants' enculturation/acculturation, language use, and parenting were linked to their oral and written language proficiencies in multilingual Hong Kong (speak English, speak Cantonese, read and write Chinese). Participants in this study included 655 immigrant parents (from Pakistan, Nepal, India, Philippines, Indonesia, Kenya, Bangladesh, Malaysia, and others). Structural equation modelling of survey responses showed that parents with greater ethnic enculturation or host acculturations reported better mainstream language skills (speak English, speak Cantonese, read and write Chinese). More heritage cultural knowledge was linked to better spoken Cantonese. Greater cultural identification with their own ethnic community was linked to better spoken English. Those with more local Chinese cultural knowledge reported better Chinese reading and writing and permissive parenting, which contributed to better English speaking. Compared to immigrant fathers, immigrant mothers reported lower Cantonese and English speaking proficiencies. Together, these results show that greater cultural identification with the ethnic community was linked to greater English-speaking skills.