Nature-based solutions (NBS) are increasingly attracting interest in research and practice due to their potential to address climate change, while at the same time safeguarding biodiversity and improving human well-being. The effective and efficient integration of NBS into Nordic planning and action, however, is still developing. This report, based on the S-UMMATION project, investigates enabling and constraining factors for effective and efficient implementation of NBS through interpretative case study analysis of eight NBS-projects in the Nordics. The report summarises experiences, derives insights and collects lessons-learnt, relevant for the future development of NBS in the Nordics. The S-UMMATION-project was carried out under the Nordic Council of Ministers (NCM) program on Nature-based solutions (NBS).