Introduction. During 2020, circulation of other respiratory viruses was lower than usual. Most likely, as mitigation measures for coronavirus disease 2019 (COVID-19) were modified, their prevalence in 2021 may have increased. Objective. To estimate the prevalence of common respiratory viruses among patients aged 0-5 years seen at the Emergency Department of a children's hospital in the City of Buenos Aires. Methods. Cross-sectional study of 348 patients consulting for suspected COVID-19 in whom SARS-CoV-2 infection was ruled out and routine screening for common respiratory viruses was performed. Results. Respiratory syncytial virus (RSV), a common respiratory virus, was identified in 40% of patients. Age younger than 2 years was an independent predictor of RSV (odds ratio [OR]: 4.15; 95% confidence interval [CI]: 2.46-6.99). Conclusion. In the study population, 40% of patients suspected of COVID-19 in whom SARS-CoV-2 infection was ruled out had RSV infection.