AIMS: To highlight the increasing importance of pests and pathogens to Australian Acacia species, both where they are planted as non-natives in commercial plantations as well as in their native environment. LOCATION: Africa, Asia, Australia, South America METHODS: Existing literature and results of unpublished surveys on pests and pathogens of Australian acacias are reviewed. These are discussed within the context of a growing importance of invasive alien insects and pathogens including novel encounters and host jumps. RESULTS: Australian acacias planted as non-natives in various parts of the world are increasingly threatened by pests and pathogens. These include those that are accidentally being introduced into the new environments as well as “new encounter’ pests and pathogens that are undergoing host shifts to infect non-native acacias. Furthermore, insects and pathogens for biological control of invasive Australian acacias present substantial challenges for plantation forestry. MAIN CONCLUSIONS: Pests and pathogens will seriously challenge plantation forestry based on non-native Australian acacias. In the longer term, new encounter pests and pathogens will also threaten these trees in their native environments.