Urban green and blue space interventions may bring about unintended consequences, involving trade-offs between thedifferent land uses, and indeed, between the needs of different urban inhabitants, land users, and owners. Such trade-offs include choicesbetween green/blue and non-green/blue projects, between broader land sparing vs. land sharing patterns, between satisfying the needsof the different inhabitants, but also between different ways of arranging the green and blue spaces. We analyze investment and planninginitiatives in six case-study cities related to green and blue infrastructure (GBI) through the lens of a predefined set of questions—ananalytical framework based on the assumption that the flows of benefits from GBI to urban inhabitants and other stakeholders aremediated by three filters: infrastructures, institutions, and perceptions. The paper builds on the authors' own knowledge and experiencewith the analyzed case-study cities and beyond, a literature overview, a review of the relevant city documents, and interviews with keyinformants. The case studies indicate examples of initiatives that were intended to make GBI benefits available and accessible to urbaninhabitants, in recognition of GBI as spaces with diverse functionality. Some case studies provide examples of trade-offs in trying toplan and design a green space for multiple private and public interests in densely built-up areas. The unintended consequences mosttypically resulted from the underappreciation of the complexity of social–ecological systems and—more specifically—the complexityof the involved infrastructures, institutions, and perceptions. The most important challenges addressed in the paper include trade-offsbetween the different ways of satisfying the residents' different needs related to the benefits from ecosystem services, ensuring properrecognition of the inhabitants' needs and perceptions, ecogentrification, caveats related to the formalization of informal spaces, andthe need to consider temporal dynamics and cross-scale approaches that compromise different goals at different geographical scales.