Résumé : The objective of the study was to assess the levels of contamination by heavy metals near the Algiers metropolis, using a combination of chemical and toxicological data gained from analyses of sediments and biological parameters characteristic of the sea urchin, Paracentrotus lividus. Zinc, lead, cadmium, copper, and iron concentrations were determined in sediments and in sea urchin gonads. Sediment toxicity was assessed by bioassay based on the larval development of sea urchins. The most numerous larval abnormalities were found in a site near Algiers identified as highly polluted by lead. The levels of the other metals across the study area fell within the background concentrations reported in the literature for the Mediterranean Sea, with the exception of zinc, which showed high values in female gonads. © 2008 International Council for the Exploration of the Sea. Published by Oxford Journals. All rights reserved.