Migrants and women were among the groups most adversely affected by the COVID-19 pandemic global disaster. Through an intersectional lens that considers both migrant and female identities, it can be inferred that migrant women were particularly vulnerable to the pandemic. This study aims to investigate the impact of the pandemic on migrant women living in Milan (North-West Italy), by leveraging on the accounts of a pool of key informants (KIs). We performed an in-depth retrospective qualitative study using semi-structured interviews to explore the perspectives of KIs working in third sector organizations and public hospitals. After conducting an extensive mapping of organizations with experience working with migrants providing health, social, and/or administrative services during the pandemic, 28 KIs working in seven organizations were recruited. Interviews were transcribed and inductively analyzed. Overall, the COVID-19 pandemic exacerbated pre-existing vulnerability factors affecting migrant women by triggering several cascading effects. The shutdown of services further marginalized them and hindered their regularization and empowerment path. Migrant women's financial situation was significantly impacted, as in most instances they had informal and gendered jobs. Caregivers and sex workers were the sub-groups most adversely affected by the pandemic. Episodes of gender-based violence appeared to rise, while requests for assistance declined. Accessing the vaccination campaign posed challenges for many migrant women, who at times tended to be skeptical about it. Third sector organizations, despite being confronted with several challenges, proved to be resilient during the pandemic and managed to find alternative methods to support migrant women, often filling institutional gaps.