Our article aims to analyze the contributions of the Secular Franciscan Order (OFS) in the construction of Integral Ecology and its relations with the urban environment. The city is a space inwhich the biodiversity crisis has worsened, with its proximity to cement constructions, with air, visual and acoustic pollution, the transport crisis, the agglomeration of population masses and the lack of natural environments. In the encyclical Laudato Si, Pope Francis emphasizes the importance of thinking about integral ecology in the urban environment. We sought in the documents of the OFS, in general, and in the actions of the service of Justice, Peace and Integrity of Creation (JPIC) the way in which the secular franciscans, based on a spirituality inherited from St. Francis of Assisi, called ecospirituality, make themselves part of the urban environment, influencing not only reflection, the experience of faith, but also concrete actions in search of eliminating the biodiversity crisis. As a result, we found a documentary support of the OFS, enabling the secular franciscans, individually and collectively, to structure their actions.