Objective: To analyze the impact of the COVID-19 pandemic on dentists' income and to identify associated factors in one of the poorest Brazilian states. Material and Methods: A cross-sectional study including dentists who volunteered to answer an electronic questionnaire in Maranhão. Hierarchical multinomial logistic regression analyses were performed, estimating crude and adjusted odds ratios (OR) and respective 95% confidence intervals (95%CI) (alpha=5%). Results: The COVID-19 pandemic impacted the professionals´ income negatively [55.44% (50.26-60.52%)] and also positively [6.9% (4.55-9.94%)]. The negative impact on income was greater among male dentists (OR=2.54; 95%CI: 1.16-5.53), over 30 years of age (OR=3.03; 95%CI: 1.34-6.87), with family income below two minimum wages (OR=4.63; 95%CI: 1.50-14.30), who worked in the continent instead of in the capital island (OR=2.21; 95%CI: 1.14-4.29) and in the private sector (OR=31.43;. Moreover, those who had been tested for COVID-19, with a negative result, had a 21.3-fold greater chance of having an increased household income when compared to those who had not been tested. Conclusion: The COVID-19 pandemic negatively impacted the dentists' income in Maranhão, especially the older, males, with lower incomes, and who worked in the private sector, living far from the capital. The SUS played an important role in the social protection of dentists during the COVID-19 pandemic, mitigating the economic impacts on the public sector working class.