The results of a four-year period (1981-1984) of monitoring heavy metals in two dumping sites for TiO2-wastes off the Belgian coast are reported. Fe, pH and dissolved oxygen were determined. Two extraction procedures were chosen for the sediments: a total destruction with HF and a mild extraction with acetic acid; Fe, V, Cr, Zn, Al, and Ti were assessed. In four benthic organisms and in shrimps and four fish species (only in 1982), Fe, Ti, Cr, Zn, Ni, Pb, Hg, Cd, and Cr were determined. An increase in heavy metal content was not noted, probably due to the favorable hydrodynamic pattern of the dumping sites. On the contrary, in the coastal reference zone, a higher iron content in the water and a higher load of most heavy metals in the sediments were noted.