Background: The women's rights movement advocates for gender equality and has a history of significant collective action. Objectives: This study aims to comprehend participation in the 8M march in Latin America by exploring SIMCA variables, including politicized identity, collective self-efficacy, group emotions, perception of injustice, and moral obligation. Method: We employed a correlational design and conducted a mediation analysis, gathering responses from 300 participants through a questionnaire. Results: These variables were found to be associated with 8M participation, with the exception of collective self-efficacy. All variables, except for moral obligation, served as mediators between politicized identity and participation. The participation repertoire was not correlated with well-being or the perception of the social climate but did show a connection with a higher intention to support the group. Discussion: The results lend support to the SIMCA theory and suggest that these variables work together to influence participation. However, collective self-efficacy did not exhibit a significant relationship.