Background and Objective: A growing body of research shows a beneficial effect of exposure to green spaces on cardiometabolic health, although the evidence is limited by the cross-sectional design of most studies. This study Aims at examining the long-term associations of residential greenness exposure with metabolic syndrome (MetS) and MetS components, in Luxembourg. Methods: We used data of 395 adults participating in both waves of the population-based ORISCAV-LUX study (Wave 1: 2007-2009, Wave 2: 2016-2017), who had no MetS at baseline. Exposure to total greenness and tree coverage were calculated for each residential address based on satellite derived Soil Adjusted Vegetation Index (SAVI) and Tree Cover Density (TCD) indices. Within- between-effect logistic and linear models were fitted to estimate both within- and between-subject variation of residential greenness on MetS and MetS components (waist circumference, triglycerides, HDL-cholesterol, fasting plasma glucose, blood pressure), respectively. Models were adjusted for several individual and neighbourhood-level confounders and for neighbourhood self-selection. Results: A 10% within-person increase in the residential TCD over a 9-year period was associated with a 74% decrease in the odds of developing MetS and better lipid profiles (βHDL-c=2.32, 95% CI : 1.08, 3.55; βtriglycerides= -6.46, 95% CI :-11.85, -1.07). Higher between-subject exposure to SAVI and TCD was associated with lower fasting plasma glucose (β: -1.22, 95% CI: -2.1, -0.35), and higher waist circumference (β: 1.08, 95% CI: 0.13, 2.02), respectively. Effect modification by sex and neighbourhood socioeconomic status were observed for triglyceride and fasting plasma glucose levels. Conclusions: This study provides new evidence that residential greenness may play a role in preventing MetS. Based on our results, we advocate for urban greening policies and programs that promote greater density of tree cover to generate additional cardiometabolic health benefits.