Background The novel 2019 SARS2-Coronavirus (COVID-19) has had a devastating physical health, mental health, and economic impact, causing millions of infections and hundreds of thousands of deaths. While COVID-19 has impacted the entire world, COVID-19 has disproportionately impacted low-income countries, particularly in South America, causing not only increased mortality but also increased associated mental health complaints. Anxiety sensitivity (AS), reflecting fear of anxiety-related physical sensations, may be particularly important to understand COVID-19 mental health effects among Latinx individuals in South America (Argentina). Past work suggests that Latinx individuals report greater somatization of mental health symptoms, and AS has been specifically linked to greater mental health symptoms. Yet, to date, no work has examined AS as a vulnerability factor for the negative mental health effects of COVID-19. Method Therefore, the current manuscript examined the association of AS with COVID-19 worry, functional impairment, anxiety, and symptom severity across two samples of adults in Argentina: a community sample (n = 105, M age = 38.58, SD = 14.07, 69.5% female) and a clinical sample comprised of individuals with an anxiety disorder (n = 99, M age = 34.99, SD = 10.83, 66.7% female). Results Results from the current study provide support for AS as a potential vulnerability factor for COVID-19-related mental health problems across both samples, and these effects were evident over and above the variance accounted for by age, sex, pre-existing medical conditions, and COVID-19 exposure. Conclusions These data identify AS as a potential intervention target to reduce COVID-19 mental health burden among adults in Argentina.