Abstract: Disclosed herein is a method for the removal of organic and inorganic contaminants from contaminated sediment or soil. The method comprises a first step of removal and disposal of very large debris while the smaller particle flow is directed to a second step of removal of organic contaminants preferably by means of attrition cell, conditioning tank and flotation columns, the remaining particulate flow, free of organic contaminants, is directed to a third step of removal of inorganic contaminants preferably by means of hydrocycloning to separately deal with very small particles of less than 20 microns, both particulate flows are then preferably subjected to column flotation to separate out the inorganic contaminants. Thus, the method of the present invention yields decontaminated soil or sediment and two distinct contaminant concentrates (organic and inorganic, respectively). Both concentrates can be recovered and used for various applications.