The OECI is a non-governmental, non-profit Organisation founded in Vienna in 1979 and remodelled in 2005 into OECI-EEIG, a European Economic Interest Grouping, headquartered in Brussels. Today, the OECI counts 100 Member Institutes, which include some of the most prominent European Comprehensive Cancer Centres. The OECI aims to create a critical mass of expertise and competences, contributing to the production and dissemination of knowledge, so as to reduce fragmentation and increase competitiveness. These goals are being achieved by promoting and strengthening the concept of “comprehensiveness”, supporting quality in cancer care also through a well-structured internal organisation. OECI aims to accelerate the production and application of personalised care approaches, and to ensure equal rights to all cancer patients, with the ultimate goal of finding new and better treatments, providing more comprehensive care and improving patient quality of life, through evidence-based medicine. The increasing interest from international organisations, stakeholders & cancer community in the OECI points to the growing importance of a comprehensive cancer network of institutions, where the entire chain of cancer care provision is present.