Millions of cubic meters of sediments are dredged every year for maintenance of canals and harbors. Dredged materials should be relocated in the original water body, but treatment or controlled disposal are necessary if contamination levels are not compatible with relocation. Sediment remediation results in greater technical problems and in higher costs compared with soil one due to specific properties of sediments (high moisture content, large amount of fine-grained particles, high organic matter content, possible presence of different types of pollutants etc.). In this work, technologies for the remediation of contaminated sediments have been investigated. The main experimental activities have been done on a new treatment system based on Stabilization/Solidification (S/S) and subsequent thermal desorption. Experimental activities were carried out on sediments polluted by mercury and petroleum hydrocarbons sampled from some Italian National Priority Sites. Chemical oxidation and reduction treatments were also investigated on sediments contaminated by petroleum hydrocarbons, PAHs and PCBs from industrial canals of Porto Marghera, Venice (Italy) and of New York City (USA).