<p>The global trophic structure and trophic level of estuarine-associated fishes was analysed in relation to biogeographic and selected environmental parameters. Meta-assemblages of estuary-associated fishes were collated at the marine ecoregional level and analysed at a broad biogeographical (bioregion) level. The fish assemblages were compared, based on feeding mode functional groups (guilds) and fish trophic levels. Relationships between these guilds and fish trophic levels and selected environmental characteristics and fish functional attributes were also examined. Significant differences were observed between bioregions in the relative species contribution of functional groups and their trophic levels. Sea surface temperature, which is often related to latitude, appeared to be a major factor associated with the relative contribution and trophic levels of estuary-associated fishes within each bioregion. Zoobenthivores dominated the species composition in all bioregions, highlighting the importance of the benthic food chain in estuarine fish communities. Differences in feeding guilds and trophic levels were also observed between bioregions and this was attributed to geographical differences in the relative contributions of the various feeding guilds, which occupy different trophic levels as well as bioregional differences in the trophic levels within the feeding guilds themselves. These variations were linked to the diversity and ability of fishes to process low quality (trophic level) food at low latitudes. The significance of these findings in relation to global climate change pressures are discussed. Generalised estuarine food webs that contrast tropical and cool-temperate bioregions are also presented, with the key role of detritus in conferring stability to estuarine food webs being emphasized.</p>