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e Summary. The scientific literature reports dozens of bioassay-based methods for the assessment of the sediment quality, many of them even officially standardized by national or international organizations (ASTM, OECD, ISO, EPA, etc.). Each one offers specific advantages, and suffers of possible disadvantages, but practically all have two major drawbacks: they are usually time-con-suming (especially in the case of chronic bioassays), and fail to univocally identify the actual cause of the detected toxicity or the detected impairment of the investigated biological characteristic(s). Therefore, this paper will review the possible use of “sediment quality guidelines ” (SQG), i.e. “nu-merical chemical concentrations intended to be either protective of biological resources, or predic-tive of adverse effects to those resources, or both”. Key words: bioassays, guidelines, sediment quality assessment. Riassunto (Saggi biologici nella valutazione della qualità dei sedimenti). La letteratura scientific