Abstract This cross-sectional study examined factors associated with occupational stress among 384 dentists working in the private sector in the first year of the COVID-19 pandemic in Brazil. Data were collected from August to October 2020 through an online form. Two outcomes - (1) anxiety and worry and (2) preparation and safety for work during the pandemic - constituted a proxy for occupational stress. The independent variables were grouped according to the explanatory theoretical model into individual, organisational and extra-organisational factors. Associations were tested by bivariate and multivariate logistic regression. Although prepared and confident, dentists felt anxious and worried about providing clinical care. Women, younger respondents and those who received no guidance on safety measures were more likely to report insecurity and unpreparedness. Younger professionals, those who did not participate in decision-making and who only sometimes had an assistant for four-hand work, were more likely to feel anxious and worried. In addition to individual factors, work organisation factors were associated with occupational stress among dentists in the first year of the pandemic.