As a response to the economic crisis and sustainability challenges the world is facing, the discussion related to green growth and green economy was launched by the Organisation for Economic Co-operation (OECD) and United Nations Environment Programme. Green growth and green economy have been seen as opportunities to foster economic growth and development, while ensuring that natural assets continue to provide the resources and ecosystem services on which our well-being relies. The central message is that greening the economies can help to generate new jobs and skills, promote clean technologies, and reduce environmental risks and poverty. This report summarises the key results of a PEER project analysing the green economy. The project explored green economy concepts and 10 practical cases from Finland, France, Germany, the Netherlands and Denmark. The work is based on three article manuscripts and thus divided into three parts: 1) a conceptual and methodological framework for the implementation and the monitoring of the different dimensions of a green economy (Loiseau et al., 2015), 2) critical factors for achieving a green economy in practice (Pitkänen et al., 2015), and 3) governance factors with respect to institutional frameworks that may facilitate a transition to a green economy (Droste et al., 2015). The concept of a green economy can encompass several meanings and be related to different economic theories, concepts and practical approaches aiming to achieve environmental, economic and social benefits. In order to measure the effects of these solutions, different assessment tools can be used. The concepts and practical approaches related to the green economy are varyingly implemented in the cases of enhancing green economy in practice. For instance, principles of industrial ecology lie behind several of our case study approaches. Similarly, circular economy and waste hierarchy concepts were present in several of the studied cases, combined for instance with energy or material efficiency approaches. The results emphasise that transitioning to green economies is never purely based on win-win solutions, but requires taking into account potential trade-offs among multiple goals, across sectors and international leakage. The case studies indicate the need for far-sighted and multiple-source planning of funding of green economy initiatives. The results emphasise a better and more holistic integration of research in green economy initiatives and projects from the beginning. As illustrated by our study, the complexity and multi-sectoral nature of the green economy calls for a broad co-integration of policies bridging the environment, innovation, transport, housing, energy, agriculture and spatial planning. Our case studies also illustrate the need for comprehensive analysis of the effects of regulation and legislation. Many of our cases also illustrate the importance of stakeholder commitment, good leadership and coordination. Transforming the economy requires innovation in terms of available technology, organisational support, market and broader societal conditions, and an overarching governance framework, but most of all, political will. The practical implementation of the green economy is related to a multiplicity of factors and causalities depending on the context. Some solutions are more compliant with the mainstream economy and require few changes (e.g. cleaner production), whereas other solutions are more system-oriented and based on profound transformations in the patterns of production and consumption (e.g. industrial ecology).