Nitroaromatic compounds, including 2,4,6-trinitrotoluene, RDX, HMX, tetryl, and associated degradation products, are released into the environment during the manufacturing, loading, packing, and assembling of munitions at U.S. Army Ammunition Plants. With the exception of 2A46DNT, nitroaromatic compounds are more toxic to fresh-water fishes (LC50s ranging from 0.4–32 mg/L) than to freshwater invertebrates (EC50s ranging from 3–100 mg/L). Rainbow trout are the most sensitive test species with LC50 values ranging from 0.43 to 6.4 mg/L for TNT, RDX, and HMX. These compounds produce negative effects on reproductive endpoints in terrestrial mammals at doses >1 mg/kg/day. Limited data indicate that nitroaromatics are not toxic to terrestrial plants (LOECs ranging from 25–100 νg/g in soil) and soil invertebrates (LOEC of 200 νg/g). Additional studies need to be undertaken to completely characterize the toxicity of these compounds; however, the criteria and screening benchmarks presented in this paper can be used to assess the risks to indigenous flora and fauna at Army Superfund sites.