COVID-19 pandemic modified the epidemiology and the transmission of Respiratory Syncytial Virus (RSV). We collected data on RSV positivity and incidence using a rapid antigen immune chromatography test from children hospitalized in the largest tertiary pediatric hospital in Greece before (2018-20, period A), during (2020-21, period B) and after (2021-23, period C) the COVID-19 lockdown. A total of 9508 children were tested for RSV. The RSV positivity(%) during the whole study period was 14.1% (1337/9508) -17.6% (552/3134) for period A, 2.1% (13/629) for period B and 13.4% (772/5745) for period C (p<0.001). The mean age (±SD) of RSV positive children among the three periods were: A:5.9 (±9.3), B:13.6 (±25.3) and C:16.7 (±28.6) months (p<0.001). The peak of RSV epidemiology was shifted from January-March (period A) to October-December (period C). The RSV in-hospital incidence per 1000 hospitalizations in pediatric departments was: