The rationale and conceptual basis for the use of sediment toxicity assays are discussed in relationship to their use in sediment evaluations employing faunal surveys, toxicity assays, and chemical analyses. The disadvantages and advantages of various species from the major classes of aquatic organisms for use as sediment toxicity assay organisms are presented. Relative sensitivities of selected species and their ease of laboratory culture and utility as assay organisms are used to rank assays and propose a battery of assays for the rapid screening evaluation of sediment toxicity. The usefulness of a battery of assays for the screening evaluation of sediment toxicity and statistical considerations which are important in the development of study designs and the analysis of results from the battery of proposed assays are discussed. The assays recommended for inclusion in the screening battery for evaluation of sediment toxicity are Microtox, an algal assay, the Chironomus tentans 10-d growth assay, and the 48-h Daphnia magna acute assay.