The database containing the library of industrial symbiosis case studies and linked exchanges has been developed as part of the activities carried out by the Centre for Industrial Sustainability, University of Cambridge, in the project MAESTRI ‘Energy and resource management systems for improved efficiency in the process industries’. This project has been funded by the European Commission through the Horizon 2020 programme. The dataset is a collection of information related to existing industrial symbiosis cases. Data have been gathered from publicly available sources (scientific papers, presentations, white papers, etc.), which are referenced in the dataset, and organised into different categories in order to make information more readable and easily accessible. The dataset is composed of two different and connected sections: a library of case studies and an exchanges database. The library of case studies describes each case according to a precise structure: a brief narrative of the case description is followed by five sections presenting related tacit knowledge content, such as triggering factors, preconditions and barriers. Each case in the library is identified by a numerical ID. All sources used to create the library content (scientific publications, whitepapers, industrial presentation, etc.) are also identified with a numerical ID. A combination of these two numerical IDs plus an additional sequential number univocally identifies each exchange found in the case studies. This numerical identifier serves as link between the case studies and the exchanges sections of the dataset. The exchanges database describes all the exchanges of resources from the cases included in the library of case studies. The information is categorised in two main sections, one related to companies involved and the other to materials exchanged. For each exchange, the industrial sector of the companies involved is identified using the NACE code, while the exchanged material is identified using the European Waste Classification, the European Classification of Products by Activities, and a CAS Registry Number ® in case its chemical composition is given. A description of the waste treatment is given wherever applicable, as well as some additional details regarding the synergy (final use of the exchanged flow, availability of flows’ quantities and payment details in the original source, level of completion of the exchange). A more detailed description of the library and the database can be found in MAESTRI Deliverable D4.2, accessible here: https://maestri-spire.eu/wp-content/uploads/2016/09/D4.2_MAESTRI-Prototype-library-of-case-studies_v1.0.pdf. An online version of the library and database is accessible from MAESTRI website, the Symbiosis Space: https://maestri-spire.eu/symbiosis-space/. This Space contains descriptions of each case and a downloadable spreadsheet with the data regarding the exchanges. The spreadsheet has VBA® macros to enable facilitated data queries.