Evaluation of an Urban Nature-Based Solutions Intervention on Health-Related Indicators: A Propensity Score Matching and Difference-in- Differences Study in Nantes Nord Urban Nature-based Solutions (NBS) are hypothesized to play an important role in promoting health, but most of the evidence is cross-sectional. This study aims to examine the effects of an integrated urban intervention with NBS at its core, implemented in the Nantes Nord district on residents' physical activity, social activity, environmental quality of life and social network as well as self-rated health and mental health. Analysing 902 observations from 2 datasets, pre- and post-intervention, we categorized 802 participants within Nantes Nord as the treatment group and 100 from other districts as the control group. We used Propensity Score Matching to adjust for selection bias in the dataset and Difference-in-Differences analysis to evaluate changes in physical activity, socializing activities, social networks, environmental quality of life, as well as self-rated health and mental health outcomes. Our results indicate that the urban tranformation with NBS at its core was associated with a significant increase in physical activity levels and to some extent in social ties. However, no immediate improvements were noticeable in socializing activities, environmental quality of life, or health outcomes, suggesting a latency in the broader effects of such interventions. This study underscores the immediate effects of the integrated NBS intervention on physical activity as a precursor to potentially more significant health benefits, which should be followed up with a more mid-to-long-term evaluation of such NBS interventions. Our findings advocate for the integration of connected green space corridors in urban planning to facilitate active lifestyles as sustainable commitments by local authorities and stakeholders. In Press, Journal Pre-proof In Press, Journal Pre-proof Elsevier