Time interval between onset of symptoms and COVID-19 testing in Brazilian state capitals, August 2020. Intervalo de tempo decorrido entre o início dos sintomas e a realização do exame para COVID-19 nas capitais brasileiras, agosto de 2020. OBJECTIVE: To analyze notifications of flu-like syndrome according to the time interval between onset of symptoms and testing for COVID-19. METHODS: This was a cross-sectional study using records of flu-like syndrome cases containing results of COVID-19 diagnostic tests in the Brazilian state capitals and Federal District, held on the e-SUS Notifica system, from March 1st, 2020 to August 18th, 2020. The time interval between symptom onset and testing was compared using the ANOVA test, classifying it according to test adequacy/timeliness. RESULTS: Taking 1,942,514 notifications, average time between symptom onset and testing was 10.2 days (±17.1). Among those tested, females (55.1%), people aged 20-39 years (43.8%), and the Southeast region of Brazil (43.0%) predominated. 58.8% of IgM ELISA tests were performed at an adequate time while 68.0% of rapid antigen tests were not performed at an adequate time. CONCLUSION: Inadequacy was found between symptom onset and time taken to test for COVID-19 in the Brazilian regions.