A coupled coagulation adsorption and high-temperature: Fenton oxidation treatment has been applied for the treatment of three different industrial wastewaters bearing high concentrations of hazardous pollutants. High percentages of chemical oxygen demand (COD) removal (>85% for the pesticide and security inks effluents and 65% for the cosmetics ones) were achieved in a first step using FeCl3 as coagulant and bentonite as adsorbent. This reduced dramatically the amount of H2O2 required in the further high-temperature (120 C) Fenton oxidation (HTF). Using the stoichiometric amount relative to COD around 70% of the remaining organic load was mineralized. The combined treatment allowed achieving the regional discharge limits of COD and ecotoxicity at a cost substantially lower than the solution used so far where the three wastewaters are managed as hazardous wastes. Working at high temperature would not represent an important drawback since around 90% of heat can be recovered from the treated off-stream.