(Uploaded by Plazi for the IPBES Invasive Alien Species Assessment) Invasive alien species (IAS) are a main driver of current global change and contribute significantly to decreases in biodiversity worldwide. To prevent new introductions and establishment of IAS, it is important to identify mechanisms of incursion. On 18 September 2017, Hurricane Maria, a category-5 Atlantic storm, made landfall on the Commonwealth of Dominica causing widespread destruction. Responding to the post-hurricane situation, countries and organizations provided a large range of aid including funds, medical and security support, and relief supplies. Here we report the incursion and establishment of two vertebrate IAS on Dominica during the aftermath of Hurricane Maria—the Common Green Iguana (Iguana iguana) and Cuban Treefrog (Osteopilus septentrionalis)—representing a 20% increase in vertebrate alien species on Dominica. We also report observations of Venezuela Snouted Treefrogs (Scinax x-signatus). Collectively, these species were found at four sites spread along the Caribbean and south coast of Dominica, within or near ports of entry. Invasions of I. iguana and O. septentrionalis are especially worrisome given their known impacts on native species on other Caribbean islands. Though understandable given the human impact caused by severe weather events, these incursions suggest that biosecurity is not implemented by aid-facilitating countries and organizations. With the predicted increase in hurricane intensity and frequency, we suggest basic biosecurity and training programs to reduce incursion threats of IAS during future relief and recovery initiatives. For Dominica, we recommend mitigation programs with additional biological surveys to control and better understand the number of incursion and their impact on post-Maria Dominica.