Odours emitted by multi-source facilities, like industrial complexes, have become a major concern for local authorities because the resulting annoyance in the neighbourhood is generally high compex compared to a single source one. In the case of such multi-source odour emissions especially, common chemical analyses or odour concentration measurement methods are not often applicable. This paper describes the methodology adopted for assessing the odour impact on the industrial area of the city of Salerno (Italy), caused by the co-presence of two strategic plants: wastewater treatment plant and composting plant of organic fraction of solid waste. The combination of olfactometric analyses and dispersion modelling allowed both the quantification of the odour emissions and the evaluation of their potential impact on the surrounding areas. Odour impact criteria, input parameters and emissive rate were evaluated. Results discuss and compare different emissive scenarios to assessment odour impacts in the industrial area.