Trash fishes were sampled monthly from small trawlers of Tungkang operating in the southwestern waters of Taiwan from January to December 1999. Trash fishes accounted for 40.1% of the total trawl landings in Tungkang. Trash species could be divided into the 2 main categories of economic and non-economic fish species. The catch rate of finfish species in trash fishes was 77.3%. Trash species were identified as 327 species belonging to 106 families for fish, 45 species of 14 families for shrimp, 5 species of 1 family for anomurans, 24 species of 5 families for crabs, and 6 species of 5 families for squid. The dominant organisms among the trash fish were of the Scorpaenidae and Bothidae (18 species) for teleosts, Penaeidae (9 species) for shrimp, Portunidae (13 species) for crab, and Loliginidae (2 species) for squid. Trichiurus lepturus was annually caught by small trawlers in Tungkang. Most of the fish comprising the trash fishes were caught in waters shallower than 100 m and deeper than 250 m in depth. From an analysis of body sizes of some important species in this study, it was concluded that most of these trash fishes are too small for exploitation. This phenomenon can be explained by the small mesh sizes of trawl nets used by the trawlers.