Rewilding is broadly recognized as an approach that promotes self-regulating ecological processes with no or minimal human intervention. Urban rewilding adapts this concept to cities by restoring ecological complexity in ways that accommodate human use and urban functions. Refined wilding further develops urban rewilding by engaging societal dimensions and design, framing spontaneous ecological processes through intentional spatial, aesthetic, and social considerations. Although these approaches are gaining traction in science, they remain less established in practice, and there is insufficient guidance on how to balance ecological goals with social acceptance, inclusion, and equity. Building on these foundations, this perspective introduces assisted urban rewilding as a conceptual and implementation framework that integrates self-organized ecological processes with inclusive governance, planning, and adaptive management in cities. Based on participatory research, academic literature, and knowledge co-produced through conferences, workshops, and webinars co-organized with international networks, we identify key principles and challenges for implementation. We distill lessons for implementing assisted urban rewilding as multifunctional NBS that are ecologically robust, socially balanced, and aligned with local contexts. We discuss critical considerations for scientists, urban planners, and practitioners, including navigating conflicting stakeholder values in participatory co-design; establishing long-term governance that empowers communities; managing trade-offs between public access and ecological sensitivity; and integrating assisted urban rewilding into blue-green infrastructure. We define criteria that distinguish assisted urban rewilding from related approaches, present a three-pathway framework linking context-specific planning, inclusive governance, and spatial integration, and outline a roadmap for embedding assisted urban rewilding within NBS, positioning it as an integral component.