In this Policy Brief, the authors present language barriers faced by posted workers in nine European Union countries (Austria, Belgium, Croatia, Germany, Italy, Romania, Slovakia, Slovenia and Spain) and discuss the implications these may have for their occupational safety and health (OSH). As the fastest-growing form of temporary cross-border labour mobility in the EU, posted workers are faced with language barriers which significantly limit the capacity of posted workers to realise and exercise their employment rights, including health and safety rights. The brief offers recommendations for policy that could help reduce OSH risks many posted workers are exposed to due to language barriers.