Abstract Objective: To assess association between multimorbidity and use of health services in a population diagnosed with COVID-19, in southern Brazil. Methods: This was a cross-sectional study with data from a longitudinal study carried out in the city of Rio Grande, Rio Grande do Sul, Brazil, in 2021 with all adult individuals diagnosed with COVID-19; descriptive analyses were performed and presented as proportions with 95% confidence intervals (95%CI); Poisson regression was performed and reported as prevalence ratios (PR) in order to assess association between multimorbidity (3 or more diseases) and healthcare service use. Results: In total, 2,919 participants were included, of which 40.4% had multimorbidity (≥ 2 diseases); the adjusted results showed that individuals with multimorbidity were more likely to use most of the services assessed, PR = 3.21 (95%CI 1.40;7.37), for Emergency Rooms. Conclusion: Multimorbidity was associated with using different types of health services.