The aim of the current study was to understand Australian parents’ beliefs relating to child restraint system (CRS) use and child vehicle occupant safety. Three hundred and eighty parents completed an online survey related to CRS knowledge and their beliefs about which factors (the influence of internal and external) influence child vehicle occupant safety. The online survey was active from June 2013 until November 2014. Results revealed a wide variation in parents’ beliefs relating to CRS use and child vehicle occupant safety. The majority of parents responded correctly to CRS related questions, including: the appropriate CRS for child vehicle occupants aged between four and seven years (95%); and the need to adjust CRS harnesses for each trip for optimal safety (91%). However, half of the parents (50%) held the misconception that the after-market H-harness accessory, provided additional protection to their child/ren, regardless of the context of use and 41 percent of parents incorrectly believed that their child/ren would reach the recommended height (145cm) for a safe adult seatbelt fit by the age of seven years. Parents tended to attribute the responsibility of child/ren’s vehicle occupant safety to internal factors such as their own driving abilities (64%) and their own safety compliance (64%), rather than external factors (e.g., fate [7%]).The results of the current study suggest that there are still significant gaps in Australian parents’ understanding about CRS use and child occupant safety which is important for the development and success of future child occupant safety initiatives.