Enclosure traps that quickly surround well-defined areas of habitat are perhaps the most widely used method for sampling fishes in vegetated habitats. However, relatively few data are available to evaluate the effects of habitat structure on sampling characteristics of enclosure traps. In this study, we determined how clearing efficiency and accuracy of 1-m2throw traps varied across a range of environmental conditions in the Florida Everglades by sampling within enclosed areas of marsh habitat. Throw trap clearing efficiency and sampling accuracy did not differ among two widely separated locations and appeared to be unaffected by variation in water depth, canopy height, plant cover, plant stem density, and periphyton volume. Sampling accuracy averaged 63% of fishes present after correcting for clearing efficiencies. On average, 83% of the fishes present in a throw trap were recovered. Therefore, it appeared that about 17% of the missing fishes may have burrowed into the substrate or been discarded with sorted detritus. In contrast, the remaining 20% of fishes probably avoided the throw trap. This is the first study to differentiate between potential sources of throw trap sampling errors. Importantly, density estimates obtained by throw traps were positively correlated (r= 0.82) with actual population densities. Mean fish lengths and fish size distributions obtained by throw trapping usually did not differ from actual mean lengths or fish size distributions. Finally, high concordance of fish species ranks indicated that throw traps accurately described fish community structure. Throw traps appeared to provide relatively accurate estimates of fish density, fish size, and community structure across a range of environmental conditions.