The paper presents the results from experiments on pilot scale plants concerning the possibility to integrate the organic waste and wastewater treatment cycles, using the light organic fraction produced via anaerobic fermentation of the organic fraction of municipal solid waste as a readily biodegradable organic carbon source for biological nutrient removal processes: the addition of the effluent from the fermentation unit as an external carbon source allows nitrogen and phosphorus removal of about 70–80% and the values of the effluent are in accordance with EC 271/91 Directive discharge limits. Maximal denitrification rate with fermenter effluent addition shows values close to those typical of pure methanol addition (0.3 kg N–NO3/kg VSS d) and double those obtained by primary settled sludges elutriate addition (0.14 kg N–NO3/kg VSS d). A full scale application of the approach (70,000 IPE), operating since July 1999 in northern Italy, is presented and an ASM 2 simulation is used to verify the behaviour of the whole real process.