Industrial symbiosis (IS) recognizes the exchange of waste resources and by-products between companies that do not normally cooperate in resource exchange; on the other hand, urban symbiosis (UrS) recognizes the use of solid waste in cities as input sources for industries that do not normally accept these sources. It is difficult to realize both in a pre-planned process, and there are few successful initiatives based on the exchange of waste and energy. The main objective of this research is to find out whether there are urban strategies that support the emergence, existence and development of IS and/or UrS in Slovenia. National documents, networks, projects, programs, and national statistical sources were examined. The Integrated Sustainable Urban Development Strategies (ISUSD) for eleven cities and municipalities were reviewed against ten selected indicators. The main findings are that there is intense awareness raising on IS and UrS, and adequate overall legislative support, aligned with EU legislation. Nevertheless, there has been surprisingly less waste conversion to energy recovery since 2010. The reuse of by-products either for energy or new products is non-existent or negligible. Selected main urban strategies for cities in Slovenia are far from setting more concrete guidelines for the development of IS and/or UrS. In the future, more successful integration of IS and UrS is possible in the context of regeneration development of brownfield sites.