The performance of double-focusing, sector field ICP-MS (ICP-SFMS) for the multi-elemental analysis of soft tissues following microwave-assisted digestion with nitric acid was evaluated and factors affecting method limits of detection discussed. Accuracy was assessed by replicate analyses of certified reference materials and by participation in performance evaluation programs; the precision was better than 5% relative standard deviation (RSD) for the majority of elements. Cl was the only element for which ICP-SFMS data consistently deviated from certified concentrations in the reference materials tested. Comparison between results obtained by ICP-SFMS and ICP optical emission spectrometry showed good agreement for elements present in tissues at concentrations above 2 mug g(-1). The concentrations of 68 elements in different fish and animal soft tissues (muscle, liver, kidney, lung and brain) are presented, and, where possible, compared with previously published data. (C) 2004 Elsevier B.V. All rights reserved.