<p>The inclusion of playgrounds in public open spaces is important for promoting children’s physical, mental, and social development. Playgrounds support children to be physically active, which helps prevent obesity and chronic diseases, while also enhancing motor skills, cognitive development, and social interaction. Outdoor play and exposure to green spaces can also reduce stress and improve mental well-being. Despite the importance of playgrounds, few high-quality intervention studies exist, especially in public spaces. Evaluating evidence on playground interventions is challenging due to methodological complexities, recruitment difficulties, and limited generalizability, highlighting the need for tailored, context-sensitive approaches and more robust methods. To address this gap, we present a structured, step-by-step evaluation guide for playground interventions, designed to be specific enough to provide clear direction yet generic enough for application across multiple cases and diverse contexts and recognizing that evaluation planning is often iterative rather than linear. The guide includes a preparatory phase and seven steps, covering case selection, co-creation, study design, data collection, implementation, and evaluation. It supports quasi-experimental and natural experimental designs, stakeholder engagement, and methodological rigor. Three case examples from Denmark, Australia, and the USA illustrate the guide’s practical application across diverse contexts. These examples emphasize aligning evaluation with local needs, timelines, and stakeholder involvement. A complementary checklist supports transparent and comprehensive planning and reporting. The guide aims to support researchers in evaluating high-quality playground evaluations. Ultimately, the guide will help contribute to the development of playgrounds that maximize use and promote health for children and communities.</p>