OBJECTIVE: to identify the factors associated with the use and reuse of masks among Brazilian individuals in the context of the COVID-19 pandemic. METHOD: cross-sectional study conducted in the five Brazilian regions, among adult individuals, via an electronic form disseminated in social media, addressing general information and the use of masks. Bivariate analysis and binary logistic regression were used to identify the factors associated with the use and reuse of masks. RESULTS: 3,981 (100%) individuals participated in the study. In total, 95.5% (CI 95%: 94.8-96.1) reported using masks. Fabric masks were more frequently reported (72.7%; CI 95%: 71.3-74.1), followed by surgical masks (27.8%; CI 95%: 26.5-29.2). The percentage of reuse was 71.1% (CI 95%: 69.7-72.5). Most (55.8%; CI 95%: 51.7-60.0) of those exclusively wearing surgical masks reported its reuse. Being a woman and having had contact with individuals presenting respiratory symptoms increased the likelihood of wearing masks (p</=0.001). Additionally, being a woman decreased the likelihood of reusing surgical masks (p</=0.001). CONCLUSION: virtually all the participants reported the use of masks, most frequently fabric masks. The findings draw attention to a risky practice, that of reusing surgical and paper masks. Therefore, guidelines, public policies, and educational strategies are needed to promote the correct use of masks to control and prevent COVID-19.