The 2002 World Summit on Sustainable Development (WSSD) not only focused on intergovernmental negotiations, but also called for partnerships between member states and non-state actors. To this end, the summit secretariat with the UN Department of Economic and Social Affairs (DESA) pursued a governance mode conceptually known as orchestration, softly enlisting intermediaries, in this case initiatives by and between public and private actors, to indirectly govern targets, such as member states. Even though initial conditions were adverse, every UN summit on sustainable development since then has orchestrated initiatives. Therefore, this article examines how orchestration has evolved, and what shapes this. To examine how it has evolved, it conceptualizes orchestration as thin or thick, depending on the mode of support the orchestrator offers to enlist intermediaries. To analyze what shapes this structurally on the macro-level, it scrutinizes the initiation of orchestration. To study how actors shape this on the micro-level, it conceptualizes different orchestration styles. It finds that overall orchestration of initiatives at UN summits on sustainable development has remained thin, even though UN DESA has tried to make orchestration thick. On the macro-level, UN DESA is structurally constrained by mandates and resources. On the micro-level, UN DESA initiates thin orchestration to raise awareness of non-state actors, build momentum and legitimate UN summits based on high quantities of enlisted initiatives. This creates trade-offs between orchestration styles, with thick orchestration and managing node orchestration styles potentially enlisting less initiatives. This has important implications for research assessing orchestrated initiatives.