In Brazil, the most dangerous country in the world for environmental activism, women have been fighting for space in the media to disseminate their discourse on environmental protection. Considered as “second category” until the 1980s, women had their voices silenced by patriarchal society, especially in political environments. Such silencing reflects the lack of female positioning in comprehensive and urgent struggles, such as environmental ones. Currently, the women’s fight against the extermination of nature is supported by the use of virtual space, especially the social networking site Facebook, which is favorable to the political expression of these women. The site has mainly provided a certain autonomy for the dissemination of the discourse, in addition to greater visibility and legitimacy for the environmental cause. Under these premises, our research analyzes the constitution of an activist ethos through the investigation of digital narratives disseminated by environmentalists in their Facebook profiles. The activists chosen for the research are the Brazilian Ana and Mayan. We used as a theoretical and methodological basis Discourse Analysis, as well as the studies on ethos, cyber-activism, and digital narrativity. During the research, we identified certain narrative strategies used by the environmentalists on the site, important for the constitution of the activist ethos on Facebook, as well as traits of feminist positioning and self-identification, recognizing the specificity of women’s struggle in the environmental cause, thus becoming a double activism, marked by feminist environmentalism.Keywords: ethos, environmentalism, counter-hegemonic discourse, digital narratives, Facebook.