This contribution focuses on insights derived from the development of a decision-making support tool for enhancing systems thinking in SDG implementation, and the application of such a tool to a real case, namely Sweden’s Voluntary National Review 2021. The tool – SDG Synergies – is a method designed to help decision-makers to understand how SDGs or associated targets interact in a given context. In the course of developing the Swedish VNR and operationalize policy coherence, the Government commissioned Stockholm Environment Institute (SEI) to launch a pilot project utilizing SDG Synergies process and tool to survey, assess and analyse synergies and trade-offs between the SDGs at the Swedish national level. Assessment of interactions between all 17 SDGs were carried out in a participatory process involving almost all ministries within the Government. The analysis focused on gaining a better understanding of how progress towards each of the SDGs could affect the whole system. By including second order effects the analysis identified the most influential SDGs on the system as a whole, and the three most influential goals were SDG 11: Sustainable cities and communities, SDG 17: Partnerships for the goals and SDG 4: Quality education. The analysis furthermore identified which SDGs are most positively affected by progress overall and hence might need less of explicit support and which SDGs are least positively affected by progress overall and hence might need extra support.