This concluding chapter summarises lessons learnt and key messages of the multidisciplinary discussion of the EU Cohesion Policy. This book discussed the disciplinary genealogies of this policy, and reflected on its rationale, implementation, outcomes and evaluation from multiple angles. Four fundamental lessons are identified: CP is a strategic tool for territorial cohesion that has evolved from being a regional economic policy to adopting multi/transdisciplinary approaches; the CP’s Multi-Level Governance is complex but necessary for the policy’s ambitious objectives; decision-makers should recognise that Cohesion Policy is not a one-size-fits-all policy and that the specificities of each member state and region should be taken into account, accepting multiplicity of outcomes. Finally, the tension between immediate crisis management and long-term investments is a challenge that the policy must address. The chapter concludes by emphasising the need to recognise the complexity of CP, promote multidisciplinary approaches, strengthen the policy’s long-term perspective, and promote research-policy dialogues.