The issue of regime complexity in global environmental governance is widely recognized. The academic debate on regime fragmentation has itself however been rather fragmented, with discussions circling around different concepts, including inter-organizational relations, polycentric governance, integrated management, landscape governance, environmental policy integration, coordination, mainstreaming, coherence, policy mixes, governance architectures and systems, regime complexes, institutional interaction, metagovernance and the nexus approach. Moreover, the topic of relationships between different policies is also discussed among practitioners, where the call for synergies is increasingly heard. This article brings together these discussions under the common heading of integrative environmental governance (IEG). The article provides a literature review, and argues for an IEG perspective in which the relationships between governance instruments take center stage.