International policies are challenged to create urban environments that foster active and healthy aging. This study seeks to determine the environmental and design factors that determine the use of public spaces by the elderly. using a mixed methodology that includes measurements of environmental parameters, observations and interviews with 200 elderly people during 2018 in three public spaces in the Arapiles neighborhood in Madrid. For the statistical analysis, different correlation tests have been applied between variables such as Pearson, Spearman. Mann Whitney U. Kruskal Wallis H, and chi-square. Besides, a multivariate statistical analysis is carried out to determine the degree to which environmental factors condition the use of public spaces by the elderly. The results show that the elderly represent 21% of the users of these spaces, their permanence is influenced by environmental factors such as temperature, humidity, wind speed and noise, however, only wind speed is determinant within a regression model. Besides, some elements of the design also significantly influence it, such as benches, water fountains and children's playgrounds, which coincide with the areas of preference and greater influx of elderly people. The analysis of external contexts is complex due to a large number of variables involved: however, the importance of environmental variables is highlighted and their control through an adequate design that promotes the general welfare and encourages the use of public spaces by the elderly. Important lines of research are being opened to face the challenges of 21st-century cities, to adapt to demographic change, guaranteeing the health, comfort, and quality of life of all citizens.