Seahorses and their syngnathid relatives have provided a focus for efforts to ensure sustainable use of marine resources, with new international trade controls (CITES Appendix II) implemented in May 2004. We demonstrate how a study of international trade can be used to assess relative levels of threat and set domestic research and conservation priorities. Australia has remarkably high syngnathid biodiversity with at least 14 seahorse species, two endemic sea dragon species, and 90 species of pipefishes and pipehorses found in its territorial waters. Our objectives were to quantify species, trade routes, volumes, values and temporal trends in syngnathid trade to and from Australia. We found that Australia is probably the major global supplier of dried pipehorses Solegnathus spp.. These fishes, including at least one endemic species, are sourced from trawl bycatch and comprise Australia's largest syngnathid export, by both volume and value. Research is urgently needed to evaluate the impacts and sustainability of trawling on pipehorse populations. Australia is also the sole supplier of two sea dragon species, Phycodurus eques and Phyllopteryx taeniolatus, for the live aquarium trade. Although lucrative, the number of wild-caught individuals involved in this trade was relatively low and probably of low conservation risk relative to habitat loss. Exports of seahorses and other pipefish species, and imports of all syngnathid species, are minor on a global scale, although the burgeoning aquaculture industry for seahorses requires careful evaluation for its potential impacts on wild populations.