In 2018 the Italian production of special waste amounted approximately to 143.5 Mt with an increase of 3.3% if compared to 2017 and disposal costs in the range of 160-240 €/ton, practically doubled within the last years. Many companies have therefore experienced increasing difficulties in waste managing because of both the increase in disposal costs and the collection timing required by sector operators. In order to make the production residues a new resource for other production activities, it is possible to qualify and manage the residues as by-products by creating paths of industrial symbiosis. Industrial symbiosis allows the transfer of resources (such as by-products and waste but also services and expertise) between two or more dissimilar industries and it represents a key to reduce their annual management costs achieving as well greater competitiveness. In addition to these advantages, there are environmental and social benefits that can have positive impacts not only on the individual companies involved but also on a territorial scale. The economic advantages can be more relevant where the industrial symbiosis approach takes place in a systematic way, against a specific project, allowing to obtain economic margins from the transfer of resources from one company to another. The main administrative legal instrument for the realization of industrial symbiosis is the by-product regulated in Italy by art. 184-bis of Legislative Decree 152/06 and subsequent amendments. Despite some steps forward to encourage and facilitate the use of by-products (Ministerial Decree of the Environment October 13, 2016, n.264, List of producers and users of by-products, List of by-products of the Emilia-Romagna Region), application difficulties persist in Italy, preventing a systematic and organic implementation of industrial symbiosis as a normal practice in the management of industrial production residues. The purpose of this work is to carry out an examination of the regulatory and application landscape of industrial symbiosis in Italy with particular reference to the regulation of the by-product, identifying some possible tools and measures to overcome the difficulties highlighted and to favor the use as by-products of production residues that meet specific criteria as required by current legislation.